crt: Provide __p__osplatform() for all CRT import libraries

_osplatform is available only in i386 and x64 versions of msvcrt.dll,
msvcr70.dll, msvcr71.dll and msvcr80.dll.

Include emulation of __p__osplatform() functions for all other CRT
libraries, including UCRT.

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

mingw-w64-crt/Makefile.am

diff --git a/mingw-w64-crt/Makefile.am b/mingw-w64-crt/Makefile.am
index b1b34b9..c5dcfbe 100644
--- a/mingw-w64-crt/Makefile.am
+++ b/mingw-w64-crt/Makefile.am
@@ -361,6 +361,7 @@
   misc/__badioinfo.c \
   misc/__p___initenv.c \
   misc/__p___winitenv.c \
+  misc/__p__osplatform_emul.c \
   misc/__p__osver_emul.c \
   misc/__initenv.c \
   misc/__winitenv.c \
@@ -534,6 +535,7 @@
   misc/__p__fmode.c \
   misc/__p__mbcasemap.c \
   misc/__p__mbctype.c \
+  misc/__p__osplatform_emul.c \
   misc/__p__osver.c \
   misc/__p__pctype.c \
   misc/__p__pgmptr.c \
@@ -648,6 +650,7 @@
   misc/__p__fmode.c \
   misc/__p__mbcasemap.c \
   misc/__p__mbctype.c \
+  misc/__p__osplatform_emul.c \
   misc/__p__osver.c \
   misc/__p__pctype.c \
   misc/__p__pgmptr.c \
@@ -681,6 +684,7 @@
   misc/__p__environ.c \
   misc/__p__fmode.c \
   misc/__p__mbctype.c \
+  misc/__p__osplatform_emul.c \
   misc/__p__osver.c \
   misc/__p__pgmptr.c \
   misc/__p__pctype.c \
@@ -742,6 +746,7 @@
   misc/__p__commode.c \
   misc/__p__environ.c \
   misc/__p__fmode.c \
+  misc/__p__osplatform_emul.c \
   misc/__p__osver.c \
   misc/__p__pctype.c \
   misc/__p__pgmptr.c \
@@ -795,6 +800,7 @@
   misc/msvcrt20__wgetmainargs.c \
   misc/___mb_cur_max_func.c \
   misc/__badioinfo.c \
+  misc/__p__osplatform_emul.c \
   misc/__pctype_func.c \
   misc/__pwctype_func.c \
   misc/__set_app_type.c \
@@ -838,6 +844,7 @@
 src_msvcrt40=\
   misc/___mb_cur_max_func.c \
   misc/__badioinfo.c \
+  misc/__p__osplatform_emul.c \
   misc/__pctype_func.c \
   misc/__pwctype_func.c \
   misc/__sys_errlist.c \
@@ -933,6 +940,7 @@
   misc/wctype.c
 
 src_msvcr90=\
+  misc/__p__osplatform_emul.c \
   misc/__p__osver_emul.c \
   misc/imaxdiv.c \
   misc/isblank.c \
@@ -941,6 +949,7 @@
   misc/wctype.c
 
 src_msvcr100=\
+  misc/__p__osplatform_emul.c \
   misc/__p__osver_emul.c \
   misc/isblank.c \
   misc/iswblank.c \
@@ -948,6 +957,7 @@
   misc/wctype.c
 
 src_msvcr110=\
+  misc/__p__osplatform_emul.c \
   misc/__p__osver_emul.c \
   misc/isblank.c \
   misc/iswblank.c \
@@ -955,6 +965,7 @@
   misc/wctype.c
 
 src_msvcr120=\
+  misc/__p__osplatform_emul.c \
   misc/__p__osver_emul.c
 
 src_msvcr120_app=\

mingw-w64-crt/misc/__p__osplatform_emul.c

diff --git a/mingw-w64-crt/misc/__p__osplatform_emul.c b/mingw-w64-crt/misc/__p__osplatform_emul.c
new file mode 100644
index 0000000..5e6f008
--- /dev/null
+++ b/mingw-w64-crt/misc/__p__osplatform_emul.c
@@ -0,0 +1,24 @@
+/**
+ * This file has no copyright assigned and is placed in the Public Domain.
+ * This file is part of the mingw-w64 runtime package.
+ * No warranty is given; refer to the file DISCLAIMER.PD within this package.
+ */
+
+#include <windows.h>
+
+#undef _osplatform
+static unsigned int _osplatform;
+
+unsigned int* __cdecl __p__osplatform(void);
+unsigned int* __cdecl __p__osplatform(void)
+{
+    if (!_osplatform)
+    {
+        OSVERSIONINFOA osvi;
+        osvi.dwOSVersionInfoSize = sizeof(osvi);
+        if (GetVersionExA(&osvi))
+            _osplatform = osvi.dwPlatformId;
+    }
+    return &_osplatform;
+}
+unsigned int* (__cdecl *__MINGW_IMP_SYMBOL(__p__osplatform))(void) = __p__osplatform;