stdlib: qsort and bsearch changes.

- Always use internal qsort and bsearch implementation.
- add "_r" reentrant versions.

The reasons for always using the internal versions is that the C runtime
versions' callbacks are not mark STDCALL, so we would have add bridge
functions for them anyhow, The C runtime qsort_r/qsort_s have different
orders of arguments on different platforms, and most importantly: qsort()
isn't a stable sort, and isn't guaranteed to give the same ordering for
two objects marked as equal by the callback...as such, Visual Studio and
glibc can give different sort results for the same data set...in this
sense, having one piece of code shared on all platforms makes sense here,
for reliabillity.

bsearch does not have a standard _r version at all, and suffers from the
same SDLCALL concern. Since the code is simple and we would have to work
around the C runtime, it's easier to just go with the built-in function
and remove all the CMake C runtime tests.

Fixes #9159.

include/SDL3/SDL_stdinc.h

@@ -498,6 +498,9 @@ extern DECLSPEC int SDLCALL SDL_setenv(const char *name, const char *value, int
 extern DECLSPEC void SDLCALL SDL_qsort(void *base, size_t nmemb, size_t size, int (SDLCALL *compare) (const void *, const void *));
 extern DECLSPEC void * SDLCALL SDL_bsearch(const void *key, const void *base, size_t nmemb, size_t size, int (SDLCALL *compare) (const void *, const void *));
 
+extern DECLSPEC void SDLCALL SDL_qsort_r(void *base, size_t nmemb, size_t size, int (SDLCALL *compare) (void *, const void *, const void *), void *userdata);
+extern DECLSPEC void * SDLCALL SDL_bsearch_r(const void *key, const void *base, size_t nmemb, size_t size, int (SDLCALL *compare) (void *, const void *, const void *), void *userdata);
+
 extern DECLSPEC int SDLCALL SDL_abs(int x);
 
 /* NOTE: these double-evaluate their arguments, so you should never have side effects in the parameters */

include/build_config/SDL_build_config.h.cmake

@@ -82,8 +82,6 @@
 #cmakedefine HAVE_PUTENV 1
 #cmakedefine HAVE_UNSETENV 1
 #endif
-#cmakedefine HAVE_QSORT 1
-#cmakedefine HAVE_BSEARCH 1
 #cmakedefine HAVE_ABS 1
 #cmakedefine HAVE_BCOPY 1
 #cmakedefine HAVE_MEMSET 1

include/build_config/SDL_build_config_android.h

@@ -63,8 +63,6 @@
 #define HAVE_PUTENV 1
 #define HAVE_SETENV 1
 #define HAVE_UNSETENV   1
-#define HAVE_QSORT  1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS    1
 #define HAVE_BCOPY  1
 #define HAVE_MEMSET 1

include/build_config/SDL_build_config_emscripten.h

@@ -65,8 +65,6 @@
 #define HAVE_SETENV 1
 #define HAVE_PUTENV 1
 #define HAVE_UNSETENV 1
-#define HAVE_QSORT 1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS 1
 #define HAVE_BCOPY 1
 #define HAVE_MEMSET 1

include/build_config/SDL_build_config_ios.h

@@ -55,8 +55,6 @@
 #define HAVE_PUTENV 1
 #define HAVE_SETENV 1
 #define HAVE_UNSETENV   1
-#define HAVE_QSORT  1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS    1
 #define HAVE_BCOPY  1
 #define HAVE_MEMSET 1

include/build_config/SDL_build_config_macos.h

@@ -59,8 +59,6 @@
 #define HAVE_SETENV 1
 #define HAVE_PUTENV 1
 #define HAVE_UNSETENV   1
-#define HAVE_QSORT  1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS    1
 #define HAVE_BCOPY  1
 #define HAVE_MEMSET 1

include/build_config/SDL_build_config_windows.h

@@ -135,8 +135,6 @@ typedef unsigned int uintptr_t;
 #define HAVE_CALLOC 1
 #define HAVE_REALLOC 1
 #define HAVE_FREE 1
-#define HAVE_QSORT 1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS 1
 #define HAVE_MEMSET 1
 #define HAVE_MEMCPY 1

include/build_config/SDL_build_config_wingdk.h

@@ -76,8 +76,6 @@
 #define HAVE_CALLOC 1
 #define HAVE_REALLOC 1
 #define HAVE_FREE 1
-#define HAVE_QSORT 1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS 1
 #define HAVE_MEMSET 1
 #define HAVE_MEMCPY 1

include/build_config/SDL_build_config_winrt.h

@@ -76,8 +76,6 @@
 #define HAVE_CALLOC 1
 #define HAVE_REALLOC 1
 #define HAVE_FREE 1
-#define HAVE_QSORT 1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS 1
 #define HAVE_MEMSET 1
 #define HAVE_MEMCPY 1

include/build_config/SDL_build_config_xbox.h

@@ -76,8 +76,6 @@
 #define HAVE_CALLOC 1
 #define HAVE_REALLOC 1
 #define HAVE_FREE 1
-#define HAVE_QSORT 1
-#define HAVE_BSEARCH 1
 #define HAVE_ABS 1
 #define HAVE_MEMSET 1
 #define HAVE_MEMCPY 1