Move bionic_macros.h from private to platform.

Test: treehugger
Change-Id: Ie473914f4c8924c7240b3ac22093a9daf42fc948
diff --git a/libc/private/CFIShadow.h b/libc/private/CFIShadow.h
index 84fbea5..ec87e3c 100644
--- a/libc/private/CFIShadow.h
+++ b/libc/private/CFIShadow.h
@@ -20,7 +20,7 @@
 #include <stdint.h>
 
 #include "platform/bionic/page.h"
-#include "private/bionic_macros.h"
+#include "platform/bionic/macros.h"
 
 constexpr unsigned kLibraryAlignmentBits = 18;
 constexpr size_t kLibraryAlignment = 1UL << kLibraryAlignmentBits;