[Google 4.8 Patch] For gnu-pubnames, Ignore unrecognized DW_TAGs to match gdb behavior

[Sterling Augustine]

I have checked in the enclosed patch, which makes GCC ignore
unrecognized DW_TAGs when building gnu-pubnames, instead of ICEing.
This matches GDB behavior.

Google ref:11307370

Sterling

Index: dwarf2out.c
===================================================================
--- dwarf2out.c	(revision 203902)
+++ dwarf2out.c	(working copy)
@@ -9249,7 +9249,8 @@
 	    GDB_INDEX_SYMBOL_STATIC_SET_VALUE(flags, 1);
           break;
         default:
-          gcc_unreachable ();
+          /* An unusual tag.  Leave the flag-byte empty.  */
+          break;
       }
       dw2_asm_output_data (1, flags >> GDB_INDEX_CU_BITSIZE,
                            "GDB-index flags");