Fix PR ld/13813, ld-mips-elf/comm-data.exp 64-bit ld failures for mipsisa32r2el

[Hans-Peter Nilsson]

See the PR.  As an incentive (well, hopefully) to review, after
this, the test-results would be clean for crosses to
mipsisa32r2el-unknown-linux-gnu (well, without an installed
compiler) and I'll add it to my binutils autotester.

Tested cross to mipsisa32r2el-unknown-linux-gnu,
mips-unknown-linux-gnu, mipsel-unknown-linux-gnu,
mips64vr-unknown-linux-gnu, mipsisa64-unknown-linux-gnu
(and a bunch of non-linux targets that returned at the
![istarget mips*-*-linux*] gate).

Ok to commit?

	PR ld/13813
	* ld-mips-elf/comm-data.exp (mips_comm_data_test): For N32 and N64
	tests, also specify assembler option -march=mips3.

Index: ld-mips-elf/comm-data.exp
===================================================================
RCS file: /cvs/src/src/ld/testsuite/ld-mips-elf/comm-data.exp,v
retrieving revision 1.1
diff -p -u -r1.1 comm-data.exp
--- ld-mips-elf/comm-data.exp	29 Nov 2011 12:42:10 -0000	1.1
+++ ld-mips-elf/comm-data.exp	6 Mar 2012 16:37:20 -0000
@@ -77,7 +77,9 @@ proc mips_comm_data_test { abi flag emul
     ]
 }
 
-set abis { o32 -32 elf32btsmip n32 -n32 elf32btsmipn32 n64 -64 elf64btsmip }
+# For targets that default to a specific ISA, the 64-bit -march option
+# is required to override it, like for "mipsisa32r2el-*-*".
+set abis { o32 -32 elf32btsmip n32 "-n32 -march=mips3" elf32btsmipn32 n64 "-64 -march=mips3" elf64btsmip }
 set relocs { copyreloc nocopyreloc }
 foreach { abi flag emul } $abis {
     foreach reloc $relocs {

brgds, H-P