commit 7a371bf93652573b3d57d50466d3ea22a6eebff2
from: Ben Huntsman <BHuntsman@mail2.cu-portland.edu>
via: Russ Cox <rsc@swtch.com>
date: Tue May 19 02:36:17 2020 UTC

lib9: use __builtin_return_address on IBM XL/C

commit - 20c841bac102e777a3a1723724fa5d31018fefcc
commit + 7a371bf93652573b3d57d50466d3ea22a6eebff2
blob - 7b4c3813116e9a1121042cdb9094335c9703a80d
blob + 4bb537d6701cb78d7b7ed4c2e89768dcc2b853e1
--- include/libc.h
+++ include/libc.h
@@ -385,7 +385,7 @@ extern	int	exitcode(char*);
 extern	void	exits(char*);
 extern	double	p9frexp(double, int*);
 extern	ulong	getcallerpc(void*);
-#if defined(__GNUC__) || defined(__clang__)
+#if defined(__GNUC__) || defined(__clang__) || defined(__IBMC__)
 #define getcallerpc(x) ((ulong)__builtin_return_address(0))
 #endif
 extern	char*	p9getenv(char*);