[VCRUNTIME] Allow disabling GCC attributes for SAL

Author: tkreuzer

sdk/include/vcruntime/gcc_sal.h

@@ -16,6 +16,7 @@
 #define __has_attribute(__x) 0
 #endif
 
+#ifndef _GCC_NO_SAL_ATTRIIBUTES
 #if __has_attribute(warn_unused_result)
 # undef _Must_inspect_result_
 /* FIXME: Not really equivalent */
@@ -24,3 +25,4 @@
 /* This one is 1:1 equivalent */
 # define _Check_return_ __attribute__((__warn_unused_result__))
 #endif
+#endif // _GCC_NO_SAL_ATTRIIBUTES