[sanitizer] Further split private and public sanitizer headers.

And make msan_interface.h C-compatible.

llvm-svn: 173928
diff --git a/compiler-rt/lib/interception/interception.h b/compiler-rt/lib/interception/interception.h
index 030bda7..63c5a00 100644
--- a/compiler-rt/lib/interception/interception.h
+++ b/compiler-rt/lib/interception/interception.h
@@ -19,7 +19,7 @@
 # error "Interception doesn't work on this operating system."
 #endif
 
-#include "sanitizer/common_interface_defs.h"
+#include "../sanitizer_common/sanitizer_internal_defs.h"
 
 // These typedefs should be used only in the interceptor definitions to replace
 // the standard system types (e.g. SSIZE_T instead of ssize_t)