MIPS SDE OS ABI support

This patch is to add SDE OS ABI support in GDB, which has been used in
codesourcery gdb tree for some years.

gdb:

2014-12-19  Maciej W. Rozycki  <macro@codesourcery.com>
	    Nigel Stephens  <nigel@mips.com>
	    Chris Dearman  <chris@mips.com>
	    Luis Machado  <lgustavo@codesourcery.com>

	* Makefile.in (ALL_TARGET_OBS): Add mips-sde-tdep.o.
	(ALLDEPFILES): Add mips-sde-tdep.c.
	* mips-sde-tdep.c: New file containg SDE specific code.
	* configure.tgt (mips*-sde*-elf*): Add mips-sde-dep.o to
	gdb_target_obs.
	* defs.h (gdb_osabi): Add GDB_OSABI_SDE.
	* osabi.c (gdb_osabi_names): Add SDE.
	* NEWS: Mention the change.
Fix undefined weak symbol reloc tests

ld/testsuite/

	* ld-mips-elf/mips-elf.exp: Update undefweak-overflow tests.
	* ld-mips-elf/undefweak-overflow-n32.d: Remove.
	* ld-mips-elf/undefweak-overflow-n64.d: Likewise.
	* ld-mips-elf/undefweak-overflow.s: Set mips64r6, noreorder and
	add a label to mark the micromips region.
	* ld-mips-elf/undefweak-overflow.d: Update expected output.
Fix all failing FPXX tests for tx39-elf.

ld/testsuite/

	* ld-mips-elf/attr-gnu-4-00.d: Relax check for ISA extension.
	* ld-mips-elf/attr-gnu-4-01.d: Likewise.
	* ld-mips-elf/attr-gnu-4-02.d: Likewise.
	* ld-mips-elf/attr-gnu-4-03.d: Likewise.
	* ld-mips-elf/attr-gnu-4-08.d: Likewise.
	* ld-mips-elf/attr-gnu-4-10.d: Likewise.
	* ld-mips-elf/attr-gnu-4-11.d: Likewise.
	* ld-mips-elf/attr-gnu-4-18.d: Likewise.
	* ld-mips-elf/attr-gnu-4-20.d: Likewise.
	* ld-mips-elf/attr-gnu-4-22.d: Likewise.
	* ld-mips-elf/attr-gnu-4-28.d: Likewise.
	* ld-mips-elf/attr-gnu-4-30.d: Likewise.
	* ld-mips-elf/attr-gnu-4-33.d: Likewise.
	* ld-mips-elf/attr-gnu-4-38.d: Likewise.
	* ld-mips-elf/attr-gnu-4-44.d: Likewise.
Fix octeon3 tests for targets with default abi != n32

gas/testsuite/

	* gas/mips/octeon3.d: Switch to use numeric register names.
Rework the alignment check for BFD_RELOC_MIPS_18_PCREL_S3.

gas/

	* config/tc-mips.c (md_apply_fix): Apply alignment check
	to the symbol and offset rather than *valP for
	BFD_RELOC_MIPS_18_PCREL_S3.  Also update the error message
	for BFD_RELOC_MIPS_19_PCREL_S2.

gas/testsuite/

	* gas/mips/r6-64.s: Remove .align directives from LDPC
	instructions and add further tests for LDPC.
	* gas/mips/r6-64-n32.d: remove the NOPs from LDPC expected
	output and update for new tests.
	* gas/mips/r6-64-n64.d: Likewise.
	* gas/mips/ldpc-unalign.l: New file.
	* gas/mips/ldpc-unalign.s: Likewise.
	* gas/mips/mips.exp: Run ldpc-unalign test.
Automatic date update in version.in