Compilation problem in bfdio.c using mingw.org's MinGW

[Eli Zaretskii]

When building the latest snapshot of GDB 13 with mingw.org's MinGW
tools, I bumped into the following compilation error:

       CC       bfdio.lo
     bfdio.c: In function '_bfd_real_fopen':
     bfdio.c:130:28: error: implicit declaration of function 
'___lc_codepage_func' [-Werror=implicit-function-declaration]
       130 |    const unsigned int cp = ___lc_codepage_func();
           |                            ^~~~~~~~~~~~~~~~~~~

This happens because the proper prototype of ___lc_codepage_func is
defined under a condition that is only valid for MinGW64:

  #if defined(__MINGW64_VERSION_MAJOR) && __MINGW64_VERSION_MAJOR < 9
  /* This prototype was added to locale.h in version 9.0 of MinGW-w64.  */
  _CRTIMP unsigned int __cdecl ___lc_codepage_func(void);
  #endif

mingw.org's MinGW doesn't define __MINGW64_VERSION_MAJOR, and it lacks
the prototype of ___lc_codepage_func in all of its versions.
Therefore, I suggest the following fix to satisfy both flavors of
MinGW:

--- bfd/bfdio.c~0       2022-12-17 03:47:10.000000000 +0200
+++ bfd/bfdio.c 2022-12-17 16:45:38.067750000 +0200
@@ -31,8 +31,10 @@
 #include <locale.h>
 #endif
 
-#if defined(__MINGW64_VERSION_MAJOR) && __MINGW64_VERSION_MAJOR < 9
-/* This prototype was added to locale.h in version 9.0 of MinGW-w64.  */
+#if (defined(__MINGW64_VERSION_MAJOR) && __MINGW64_VERSION_MAJOR < 9)  \
+  || (defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR))
+/* This prototype was added to locale.h in version 9.0 of MinGW-w64,
+   and is absent from all versions of mingw.org's MinGW.  */
 _CRTIMP unsigned int __cdecl ___lc_codepage_func(void);
 #endif