Introduce new error handling API.

This will replace exit()/abort() style error handling with an API
that allows clients to register custom error handling hooks.
The default is to call exit(1) when no error handler is provided.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74922 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Support/Compiler.h

@@ -56,4 +56,10 @@
 #define DISABLE_INLINE
 #endif
 
+#ifdef __GNUC__
+#define NORETURN __attribute__((noreturn))
+#else
+#define NORETURN
+#endif
+
 #endif