Darwin - fix PR c++/87380

This is [intentionally] broken C++ ABI, that was catering for a
tool problem that existed in a very old Darwin toolchain.

The issue is not present after Darwin7 (using default system
tools) so confine the fix to that revision or earlier.

2018-12-06  Iain Sandoe  <iain@sandoe.co.uk>

	PR c++/87380
	* config/darwin.h (TARGET_WEAK_NOT_IN_ARCHIVE_TOC) Remove; use the
	default.
	* config/rs6000/darwin7.h (TARGET_WEAK_NOT_IN_ARCHIVE_TOC): New.

From-SVN: r266866

gcc/ChangeLog

+2018-12-06  Iain Sandoe  <iain@sandoe.co.uk>
+
+	PR c++/87380
+	* config/darwin.h (TARGET_WEAK_NOT_IN_ARCHIVE_TOC) Remove, use the
+	default.
+	* config/rs6000/darwin7.h (TARGET_WEAK_NOT_IN_ARCHIVE_TOC): New.
+
 2018-12-06  Vladimir Makarov  <vmakarov@redhat.com>
 
 	PR target/88282

gcc/config/darwin.h

@@ -511,11 +511,6 @@ extern GTY(()) int darwin_ms_struct;
    links to, so there's no need for weak-ness for that.  */
 #define GTHREAD_USE_WEAK 0
 
-/* The Darwin linker doesn't want coalesced symbols to appear in
-   a static archive's table of contents. */
-#undef TARGET_WEAK_NOT_IN_ARCHIVE_TOC
-#define TARGET_WEAK_NOT_IN_ARCHIVE_TOC 1
-
 /* On Darwin, we don't (at the time of writing) have linkonce sections
    with names, so it's safe to make the class data not comdat.  */
 #define TARGET_CXX_CLASS_DATA_ALWAYS_COMDAT hook_bool_void_false

gcc/config/rs6000/darwin7.h

@@ -28,5 +28,10 @@ along with GCC; see the file COPYING3.  If not see
   %:version-compare(!< 10.3 mmacosx-version-min= -lmx)\
   -lSystem}"
 
+/* This generation of tools (specifically the archive tool) did not
+   export weak symbols from the TOC. */
+#undef TARGET_WEAK_NOT_IN_ARCHIVE_TOC
+#define TARGET_WEAK_NOT_IN_ARCHIVE_TOC 1
+
 #undef DEF_MIN_OSX_VERSION
 #define DEF_MIN_OSX_VERSION "10.3.9"