MIPS: Add new Imagination interAptiv MR2 GAS and LD tests

Add GAS tests to verify Imagination interAptiv MR2 instruction assembly,
disassembly and ELF object file flags.

Add LD tests to verify Imagination interAptiv MR2 ELF object file
link-time compatibility and flag merging/propagation.  Use the framework
enhancement added with commit 7575e6a7 ("MIPS/LD/testsuite:
mips-elf-flags: Add MIPS ABI Flags handling").

	gas/
	* testsuite/gas/mips/elf_mach_interaptiv-mr2.d: New test.
	* testsuite/gas/mips/save-err.d: New test.
	* testsuite/gas/mips/save-sub.d: New test.
	* testsuite/gas/mips/interaptiv-mr2@save.d: New test.
	* testsuite/gas/mips/mips1@save-sub.d: New test.
	* testsuite/gas/mips/mips2@save-sub.d: New test.
	* testsuite/gas/mips/mips3@save-sub.d: New test.
	* testsuite/gas/mips/mips4@save-sub.d: New test.
	* testsuite/gas/mips/mips5@save-sub.d: New test.
	* testsuite/gas/mips/mips32@save-sub.d: New test.
	* testsuite/gas/mips/mips64@save-sub.d: New test.
	* testsuite/gas/mips/mips16@save-sub.d: New test.
	* testsuite/gas/mips/mips16e@save-sub.d: New test.
	* testsuite/gas/mips/r3000@save-sub.d: New test.
	* testsuite/gas/mips/r3900@save-sub.d: New test.
	* testsuite/gas/mips/r4000@save-sub.d: New test.
	* testsuite/gas/mips/vr5400@save-sub.d: New test.
	* testsuite/gas/mips/interaptiv-mr2@save-sub.d: New test.
	* testsuite/gas/mips/sb1@save-sub.d: New test.
	* testsuite/gas/mips/octeon2@save-sub.d: New test.
	* testsuite/gas/mips/octeon3@save-sub.d: New test.
	* testsuite/gas/mips/xlr@save-sub.d: New test.
	* testsuite/gas/mips/r5900@save-sub.d: New test.
	* testsuite/gas/mips/mips16e2-copy.d: New test.
	* testsuite/gas/mips/mips16e2-copy-err.d: New test.
	* testsuite/gas/mips/save.d: Remove `MIPS16e' from the `name'
	option.  Adjust for trailing padding change.
	* testsuite/gas/mips/mips16e2-copy-err.l: New stderr output.
	* testsuite/gas/mips/save-sub.s: New test source.
	* testsuite/gas/mips/mips16e2-copy.s: New test source.
	* testsuite/gas/mips/mips16e2-copy-err.s: New test source.
	* testsuite/gas/mips/save.s: Update description, change trailing
	padding and remove trailing white space.
	* testsuite/gas/mips/mips.exp: Expand `save' and `save-err'
	tests across the regular MIPS interAptiv MR2 architecture.  Run
	the new tests.

	ld/
	* testsuite/ld-mips-elf/mips-elf-flags.exp: Add interAptiv MR2
	tests.