runtime: avoid defining the same variable in more than one translation unit
For gccgo runtime and Darwin where -fno-common is the default.
R=iant, dave
CC=golang-dev
https://golang.org/cl/7094061
diff --git a/src/pkg/runtime/runtime.h b/src/pkg/runtime/runtime.h
index 47a7b6e..e21c276 100644
--- a/src/pkg/runtime/runtime.h
+++ b/src/pkg/runtime/runtime.h
@@ -562,15 +562,15 @@
*/
extern String runtime·emptystring;
extern uintptr runtime·zerobase;
-G* runtime·allg;
-G* runtime·lastg;
-M* runtime·allm;
+extern G* runtime·allg;
+extern G* runtime·lastg;
+extern M* runtime·allm;
extern int32 runtime·gomaxprocs;
extern bool runtime·singleproc;
extern uint32 runtime·panicking;
extern int32 runtime·gcwaiting; // gc is waiting to run
-int8* runtime·goos;
-int32 runtime·ncpu;
+extern int8* runtime·goos;
+extern int32 runtime·ncpu;
extern bool runtime·iscgo;
extern void (*runtime·sysargs)(int32, uint8**);
extern uint32 runtime·maxstring;
