[UCRT] Add GCC compatible definition of _CRT_STDIO_INLINE

In C99 mode GCC emits global symbols for inline functions, as soon as the compilation unit contains a declaration that marks the function as "extern". A number of functions like printf are implicitly declared as extern by GCC, which seemingly cannot be disabled. This would lead to the inline function being emitted as a global symbol in every compilation unit. Using static inline prevents duplicate symbol errors.

Author: tkreuzer

sdk/include/ucrt/corecrt_stdio_config.h

@@ -23,7 +23,11 @@ _CRT_BEGIN_C_HEADER
     #undef _CRT_STDIO_INLINE
     #define _CRT_STDIO_INLINE
 #elif !defined _CRT_STDIO_INLINE
+  #if defined(__GNUC__)
+    #define _CRT_STDIO_INLINE static __inline
+  #else
     #define _CRT_STDIO_INLINE __inline
+  #endif
 #endif
 
 #if !defined RC_INVOKED // RC has no target architecture