[4.6] Don't emit discriminators in .debug_line if -gstrict-dwarf and not -gdwarf-4 (PR debug/50816)

[Jakub Jelinek]

Hi!

This is something that got fixed on the trunk as part of PR48400,
but in 4.6 dwarf2out_source_line is quite a bit different, emits
discriminators only when using .loc directives etc.
Ok for branch?

2011-10-24  Jakub Jelinek  <ja...@redhat.com>

        PR debug/50816
        * dwarf2out.c (dwarf2out_source_line): Emit discriminators only if
        -gdwarf-4 or not -gstrict-dwarf.

--- gcc/dwarf2out.c     2011-10-20 09:51:51.000000000 +0200
+++ gcc/dwarf2out.c     2011-10-24 18:48:13.266140198 +0200
@@ -22060,7 +22060,8 @@ dwarf2out_source_line (unsigned int line
              fprintf (asm_out_file, " is_stmt %d", is_stmt ? 1 : 0);
              last_is_stmt = is_stmt;
            }
-         if (SUPPORTS_DISCRIMINATOR && discriminator != 0)
+         if (SUPPORTS_DISCRIMINATOR && discriminator != 0
+             && (dwarf_version >= 4 || !dwarf_strict))
            fprintf (asm_out_file, " discriminator %d", discriminator);
          fputc ('\n', asm_out_file);
 

        Jakub