2015-12-22  Jack Howarth  <howarth.at.gcc@gmail.com>

boehm-gc/

	PR target/66848
	* include/private/gcconfig.h: Enforce 16-bit alignment on darwin.


Index: boehm-gc/include/private/gcconfig.h
===================================================================
--- boehm-gc/include/private/gcconfig.h	(revision 231884)
+++ boehm-gc/include/private/gcconfig.h	(working copy)
@@ -1041,10 +1041,18 @@
 #   define MACH_TYPE "I386"
 #   if defined(__LP64__) || defined(_WIN64)
 #     define CPP_WORDSZ 64
-#     define ALIGNMENT 8
+#     if defined(__APPLE__)
+#       define ALIGNMENT 2
+#     else
+#       define ALIGNMENT 8
+#     endif
 #   else
 #     define CPP_WORDSZ 32
-#     define ALIGNMENT 4
+#     if defined(__APPLE__)
+#       define ALIGNMENT 2
+#     else
+#       define ALIGNMENT 4
+#     endif
 			/* Appears to hold for all "32 bit" compilers	*/
 			/* except Borland.  The -a4 option fixes 	*/
 			/* Borland.					*/
@@ -2005,10 +2013,18 @@
 # ifdef X86_64
 #   define MACH_TYPE "X86_64"
 #   ifdef __ILP32__
-#     define ALIGNMENT 4
+#     if defined(__APPLE__)
+#       define ALIGNMENT 2
+#     else
+#       define ALIGNMENT 4
+#     endif
 #     define CPP_WORDSZ 32
 #   else
-#     define ALIGNMENT 8
+#     if defined(__APPLE__)
+#       define ALIGNMENT 2
+#     else
+#       define ALIGNMENT 8
+#     endif
 #     define CPP_WORDSZ 64
 #   endif
 #   ifndef HBLKSIZE