[compiler-rt] Fix definition of usize on 32-bit Windows

32-bit Windows uses `unsigned int` for uintptr_t and size_t.
Commit 18e06e3 changed uptr to
unsigned long, so it no longer matches the real size_t/uintptr_t and
therefore the current definition of usize result in:
`error C2821: first formal parameter to 'operator new' must be 'size_t'`

However, the real problem is that uptr is wrong to work around the fact
that we have local SIZE_T and SSIZE_T typedefs that trample on the
basetsd.h definitions of the same name and therefore need to match
exactly. Unlike size_t/ssize_t the uppercase ones always use unsigned
long (even on 32-bit).

This commit works around the build breakage by keeping the existing
definitions of uptr/sptr and just changing usize. A follow-up change
will attempt to fix this properly.

Fixes: llvm#101998

Reviewed By: mstorsjo

Pull Request: llvm#106151

compiler-rt/lib/sanitizer_common/sanitizer_internal_defs.h

@@ -194,7 +194,16 @@ typedef u64 OFF64_T;
 #ifdef __SIZE_TYPE__
 typedef __SIZE_TYPE__ usize;
 #else
+// Since we use this for operator new, usize must match the real size_t, but on
+// 32-bit Windows the definition of uptr does not actually match uintptr_t or
+// size_t because we are working around typedef mismatches for the (S)SIZE_T
+// types used in interception.h.
+// Until the definition of uptr has been fixed we have to special case Win32.
+# if SANITIZER_WINDOWS && SANITIZER_WORDSIZE == 32
+typedef unsigned int usize;
+# else
 typedef uptr usize;
+# endif
 #endif
 
 typedef u64 tid_t;