Fix handling of dwarf sections for IRIX 6

[Richard Sandiford <rsandifo at redhat dot com>]

gcc's IRIX 6 configuration will emit section statements of the form:

        .section .debug_abbrev,0x7000001e,0,0,0

where 0x7000001e == SHT_MIPS_DWARF.  This is correct in theory, but as
explained in the comment below, GAS expects the dwarf sections to have
type SHT_PROGBITS instead.  Any deviation will lead to a warning.

I've been using this patch locally for some time and it's enough to get
good gcc testresults using GNU as & ld.  OK to install?

Richard


	* config/tc-mips.c (s_change_section): When parsing the MIPS-specific
	.section syntax, map SHT_MIPS_DWARF to SHT_PROGBITS.

Index: gas/config/tc-mips.c
===================================================================
RCS file: /cvs/src/src/gas/config/tc-mips.c,v
retrieving revision 1.240
diff -c -p -F^\([(a-zA-Z0-9_]\|#define\) -r1.240 tc-mips.c
*** gas/config/tc-mips.c	6 Dec 2003 13:52:23 -0000	1.240
--- gas/config/tc-mips.c	16 Dec 2003 21:07:37 -0000
*************** s_change_section (int ignore ATTRIBUTE_U
*** 11981,11986 ****
--- 11981,12002 ----
  
    section_name = xstrdup (section_name);
  
+   /* When using the generic form of .section (as implemented by obj-elf.c),
+      there's no way to set the section type to SHT_MIPS_DWARF.  Users have
+      traditionally had to fall back on the more common @progbits instead.
+ 
+      There's nothing really harmful in this, since bfd will correct
+      SHT_PROGBITS to SHT_MIPS_DWARF before writing out the file.  But it
+      means that, for backwards compatibiltiy, the special_section entries
+      for dwarf sections must use SHT_PROGBITS rather than SHT_MIPS_DWARF.
+ 
+      Even so, we shouldn't force users of the MIPS .section syntax to
+      incorrectly label the sections as SHT_PROGBITS.  The best compromise
+      seems to be to map SHT_MIPS_DWARF to SHT_PROGBITS before calling the
+      generic type-checking code.  */
+   if (section_type == SHT_MIPS_DWARF)
+     section_type = SHT_PROGBITS;
+ 
    obj_elf_change_section (section_name, section_type, section_flag,
  			  section_entry_size, 0, 0, 0);