Refactor to remove un-named struct gnu extension usage. Now ISO C89 and C99 compliant. Comment trailing endifs

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@78537 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/config.h.cmake b/config.h.cmake
index 4f640db..ac72ee2 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -1 +1,2 @@
 #cmakedefine HAVE_SYS_BYTEORDER_H ${HAVE_SYS_BYTEORDER}
+#cmakedefine __Apple__ ${CMAKE_HOST_APPLE}