decouple internal.h headers

Saves comitters' daily life by avoid #include-ing everything from
internal.h to make each file do so instead.  This would significantly
speed up incremental builds.

We take the following inclusion order in this changeset:

1.  "ruby/config.h", where _GNU_SOURCE is defined (must be the very
    first thing among everything).
2.  RUBY_EXTCONF_H if any.
3.  Standard C headers, sorted alphabetically.
4.  Other system headers, maybe guarded by #ifdef
5.  Everything else, sorted alphabetically.

Exceptions are those win32-related headers, which tend not be self-
containing (headers have inclusion order dependencies).

array.c

@@ -10,14 +10,25 @@
   Copyright (C) 2000  Information-technology Promotion Agency, Japan
 
 **********************************************************************/
+
+#include "debug_counter.h"
+#include "id.h"
+#include "internal.h"
+#include "internal/array.h"
+#include "internal/compar.h"
+#include "internal/enum.h"
+#include "internal/gc.h"
+#include "internal/hash.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/proc.h"
+#include "internal/rational.h"
+#include "internal/vm.h"
+#include "probes.h"
 #include "ruby/encoding.h"
-#include "ruby/util.h"
 #include "ruby/st.h"
-#include "probes.h"
-#include "id.h"
-#include "debug_counter.h"
+#include "ruby/util.h"
 #include "transient_heap.h"
-#include "internal.h"
 
 #if !ARRAY_DEBUG
 # define NDEBUG

ast.c

@@ -1,11 +1,15 @@
 /* indent-tabs-mode: nil */
+#include "internal.h"
+#include "internal/parse.h"
+#include "internal/symbol.h"
+#include "internal/warnings.h"
+#include "iseq.h"
+#include "node.h"
 #include "ruby.h"
 #include "ruby/encoding.h"
 #include "ruby/util.h"
-#include "internal.h"
-#include "node.h"
 #include "vm_core.h"
-#include "iseq.h"
+
 #include "builtin.h"
 
 static VALUE rb_mAST;

bignum.c

@@ -9,27 +9,40 @@
 
 **********************************************************************/
 
-#include "internal.h"
-#include "ruby/thread.h"
-#include "ruby/util.h"
-#include "id.h"
+#include "ruby/config.h"
+
+#include <ctype.h>
+#include <float.h>
+#include <math.h>
 
 #ifdef HAVE_STRINGS_H
-#include <strings.h>
+# include <strings.h>
 #endif
-#include <math.h>
-#include <float.h>
-#include <ctype.h>
+
 #ifdef HAVE_IEEEFP_H
-#include <ieeefp.h>
+# include <ieeefp.h>
 #endif
-#include "ruby_assert.h"
 
 #if defined(HAVE_LIBGMP) && defined(HAVE_GMP_H)
-#define USE_GMP
-#include <gmp.h>
+# define USE_GMP
+# include <gmp.h>
 #endif
 
+#include "id.h"
+#include "internal.h"
+#include "internal/bignum.h"
+#include "internal/complex.h"
+#include "internal/gc.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/sanitizers.h"
+#include "internal/util.h"
+#include "internal/variable.h"
+#include "internal/warnings.h"
+#include "ruby/thread.h"
+#include "ruby/util.h"
+#include "ruby_assert.h"
+
 #define RB_BIGNUM_TYPE_P(x) RB_TYPE_P((x), T_BIGNUM)
 
 #ifndef RUBY_INTEGER_UNIFICATION

class.c

@@ -23,12 +23,20 @@
  * \{
  */
 
+#include "ruby/config.h"
+#include <ctype.h>
+
+#include "constant.h"
+#include "id_table.h"
 #include "internal.h"
+#include "internal/class.h"
+#include "internal/error.h"
+#include "internal/eval.h"
+#include "internal/hash.h"
+#include "internal/object.h"
+#include "internal/variable.h"
 #include "ruby/st.h"
-#include "constant.h"
 #include "vm_core.h"
-#include "id_table.h"
-#include <ctype.h>
 
 #define id_attached id__attached__
 

compar.c

@@ -9,9 +9,12 @@
 
 **********************************************************************/
 
-#include "ruby/ruby.h"
 #include "id.h"
 #include "internal.h"
+#include "internal/compar.h"
+#include "internal/error.h"
+#include "internal/vm.h"
+#include "ruby/ruby.h"
 
 VALUE rb_mComparable;
 

compile.c

@@ -9,25 +9,39 @@
 
 **********************************************************************/
 
-#include "ruby/encoding.h"
-#include "ruby/re.h"
-#include "ruby/util.h"
-#include "internal.h"
-#include "encindex.h"
+#include "ruby/config.h"
 #include <math.h>
 
+#ifdef HAVE_DLADDR
+# include <dlfcn.h>
+#endif
+
+#include "encindex.h"
+#include "gc.h"
+#include "id_table.h"
+#include "internal.h"
+#include "internal/array.h"
+#include "internal/compile.h"
+#include "internal/complex.h"
+#include "internal/debug.h"
+#include "internal/encoding.h"
+#include "internal/error.h"
+#include "internal/hash.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/re.h"
+#include "internal/symbol.h"
+#include "internal/thread.h"
+#include "internal/variable.h"
+#include "iseq.h"
+#include "ruby/re.h"
+#include "ruby/util.h"
 #include "vm_core.h"
 #include "vm_debug.h"
+
 #include "builtin.h"
-#include "iseq.h"
 #include "insns.inc"
 #include "insns_info.inc"
-#include "id_table.h"
-#include "gc.h"
-
-#ifdef HAVE_DLADDR
-# include <dlfcn.h>
-#endif
 
 #undef RUBY_UNTYPED_DATA_WARNING
 #define RUBY_UNTYPED_DATA_WARNING 0

complex.c

@@ -6,15 +6,25 @@
 */
 
 #include "ruby/config.h"
+
 #if defined _MSC_VER
 /* Microsoft Visual C does not define M_PI and others by default */
 # define _USE_MATH_DEFINES 1
 #endif
+
+#include <ctype.h>
 #include <math.h>
-#include "internal.h"
-#include "id.h"
 
 #define NDEBUG
+#include "id.h"
+#include "internal.h"
+#include "internal/class.h"
+#include "internal/complex.h"
+#include "internal/error.h"
+#include "internal/math.h"
+#include "internal/numeric.h"
+#include "internal/object.h"
+#include "internal/rational.h"
 #include "ruby_assert.h"
 
 #define ZERO INT2FIX(0)
@@ -1700,8 +1710,6 @@ numeric_to_c(VALUE self)
     return rb_complex_new1(self);
 }
 
-#include <ctype.h>
-
 inline static int
 issign(int c)
 {

constant.h

@@ -10,6 +10,8 @@
 **********************************************************************/
 #ifndef CONSTANT_H
 #define CONSTANT_H
+#include "ruby/ruby.h"
+#include "id_table.h"
 
 typedef enum {
     CONST_DEPRECATED = 0x100,

cont.c

@@ -9,19 +9,25 @@
 
 **********************************************************************/
 
-#include "internal.h"
-#include "vm_core.h"
-#include "gc.h"
-#include "eval_intern.h"
-#include "mjit.h"
-
-#include COROUTINE_H
+#include "ruby/config.h"
 
 #ifndef _WIN32
 #include <unistd.h>
 #include <sys/mman.h>
 #endif
 
+#include COROUTINE_H
+
+#include "eval_intern.h"
+#include "gc.h"
+#include "internal.h"
+#include "internal/cont.h"
+#include "internal/mjit.h"
+#include "internal/proc.h"
+#include "internal/warnings.h"
+#include "mjit.h"
+#include "vm_core.h"
+
 static const int DEBUG = 0;
 
 #define RB_PAGE_SIZE (pagesize)

coroutine/amd64/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn)) void

coroutine/arm32/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn)) void

coroutine/arm64/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn)) void

coroutine/ppc64le/Context.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn)) void

coroutine/win32/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __declspec(noreturn) void __fastcall

coroutine/win64/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __declspec(noreturn) void

coroutine/x86/Context.h

@@ -8,6 +8,8 @@
 #pragma once
 
 #include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <string.h>
 
 #define COROUTINE __attribute__((noreturn, fastcall)) void

debug.c

@@ -9,15 +9,22 @@
 
 **********************************************************************/
 
-#include "ruby/ruby.h"
+#include "ruby/config.h"
+
+#include <stdio.h>
+
+#include "eval_intern.h"
+#include "id.h"
+#include "internal/debug.h"
+#include "internal/signal.h"
+#include "internal/util.h"
 #include "ruby/encoding.h"
 #include "ruby/io.h"
+#include "ruby/ruby.h"
 #include "ruby/util.h"
-#include "vm_debug.h"
-#include "eval_intern.h"
-#include "vm_core.h"
 #include "symbol.h"
-#include "id.h"
+#include "vm_core.h"
+#include "vm_debug.h"
 
 /* This is the only place struct RIMemo is actually used */
 struct RIMemo {