update vendored copy of libbacktrace (#59)

motivation: catch up to fixes and improvments in underlying library

changes:
* vendor latest version of libbacktrace
* update vendoring script to exclude some new files that are not needed

Sources/CBacktrace/atomic.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* atomic.c -- Support for atomic functions if not present.
-   Copyright (C) 2013-2018 Free Software Foundation, Inc.
+   Copyright (C) 2013-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/CBacktrace/backtrace-supported.h

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* backtrace-supported.h.in -- Whether stack backtrace is supported.
-   Copyright (C) 2012-2016 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without

Sources/CBacktrace/backtrace.c

@@ -1,6 +1,6 @@
 #ifdef __linux__
 /* backtrace.c -- Entry point for stack backtrace library.
-   Copyright (C) 2012-2018 Free Software Foundation, Inc.
+   Copyright (C) 2012-2021 Free Software Foundation, Inc.
    Written by Ian Lance Taylor, Google.
 
 Redistribution and use in source and binary forms, with or without
@@ -99,7 +99,7 @@ unwind (struct _Unwind_Context *context, void *vdata)
 
 /* Get a stack backtrace.  */
 
-int
+int __attribute__((noinline))
 backtrace_full (struct backtrace_state *state, int skip,
 		backtrace_full_callback callback,
 		backtrace_error_callback error_callback, void *data)

Sources/CBacktrace/config.h

@@ -14,6 +14,10 @@
 /* Define to 1 if you have the `clock_gettime' function. */
 #define HAVE_CLOCK_GETTIME 1
 
+/* Define to 1 if you have the declaration of `getpagesize', and to 0 if you
+   don't. */
+#define HAVE_DECL_GETPAGESIZE 1
+
 /* Define to 1 if you have the declaration of `strnlen', and to 0 if you
    don't. */
 #define HAVE_DECL_STRNLEN 1
@@ -36,8 +40,16 @@
 /* Define to 1 if you have the <inttypes.h> header file. */
 #define HAVE_INTTYPES_H 1
 
-/* Define to 1 if you have the `z' library (-lz). */
-/* #undef HAVE_LIBZ */
+/* Define to 1 if you have KERN_PROC and KERN_PROC_PATHNAME in <sys/sysctl.h>.
+   */
+/* #undef HAVE_KERN_PROC */
+
+/* Define to 1 if you have KERN_PROCARGS and KERN_PROC_PATHNAME in
+   <sys/sysctl.h>. */
+/* #undef HAVE_KERN_PROC_ARGS */
+
+/* Define if -llzma is available. */
+/* #undef HAVE_LIBLZMA */
 
 /* Define to 1 if you have the <link.h> header file. */
 #define HAVE_LINK_H 1
@@ -48,6 +60,9 @@
 /* Define to 1 if you have the `lstat' function. */
 #define HAVE_LSTAT 1
 
+/* Define to 1 if you have the <mach-o/dyld.h> header file. */
+/* #undef HAVE_MACH_O_DYLD_H */
+
 /* Define to 1 if you have the <memory.h> header file. */
 #define HAVE_MEMORY_H 1
 
@@ -85,7 +100,7 @@
 #define HAVE_UNISTD_H 1
 
 /* Define if -lz is available. */
-/* #undef HAVE_ZLIB */
+#define HAVE_ZLIB 1
 
 /* Define to the sub-directory in which libtool stores uninstalled libraries.
    */
@@ -134,6 +149,11 @@
 #endif
 
 
+/* Enable large inode numbers on Mac OS X 10.5.  */
+#ifndef _DARWIN_USE_64_BIT_INODE
+# define _DARWIN_USE_64_BIT_INODE 1
+#endif
+
 /* Number of bits in a file offset, on hosts where this is settable. */
 /* #undef _FILE_OFFSET_BITS */