headers: Don't declare getpid for msvcrt versions where it's missing

If the getpid function is missing, user code might try to reimplement
it, with minor mismatches to the signature.

Signed-off-by: Martin Storsjö <martin@martin.st>

mingw-w64-headers/crt/process.h

diff --git a/mingw-w64-headers/crt/process.h b/mingw-w64-headers/crt/process.h
index 9077548..7962af1 100644
--- a/mingw-w64-headers/crt/process.h
+++ b/mingw-w64-headers/crt/process.h
@@ -60,7 +60,9 @@
 
   void __cdecl __MINGW_NOTHROW _cexit(void);
   void __cdecl __MINGW_NOTHROW _c_exit(void);
+#if !(defined(__arm__) || defined(__aarch64__)) || __MSVCRT_VERSION__ > 0x700
   _CRTIMP int __cdecl _getpid(void);
+#endif
   _CRTIMP intptr_t __cdecl _cwait(int *_TermStat,intptr_t _ProcHandle,int _Action);
   _CRTIMP intptr_t __cdecl _execl(const char *_Filename,const char *_ArgList,...);
   _CRTIMP intptr_t __cdecl _execle(const char *_Filename,const char *_ArgList,...);
@@ -173,8 +175,10 @@
   intptr_t __cdecl spawnlpe(int,const char *_Filename,const char *_ArgList,...) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
 #ifndef _CRT_GETPID_DEFINED
 #define _CRT_GETPID_DEFINED  /* Also in unistd.h */
+#if !(defined(__arm__) || defined(__aarch64__)) || __MSVCRT_VERSION__ > 0x700
   int __cdecl getpid(void) __MINGW_ATTRIB_DEPRECATED_MSVC2005;
 #endif
+#endif
 #ifdef __GNUC__
   /* Those methods are predefined by gcc builtins to return int. So to prevent
      stupid warnings, define them in POSIX way.  This is save, because those