Lit: Introduce an environment variable, $LIT_PRESERVES_TMP, to preserve TMP (and TEMP).

This is intended to check how many temporary files would be generated in automated builders.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192887 91177308-0d34-0410-b5e6-96231b3b80d8
[mips][msa] Removed ldx.[bhwd] and stx.[bhwd].

These were present in a previous version of the MSA spec but are not
present in the published version. There is no hardware that uses these
instructions.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192888 91177308-0d34-0410-b5e6-96231b3b80d8
Fix r192888: test/CodeGen/Mips/msa/3r_ld_st.ll should have been deleted


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192889 91177308-0d34-0410-b5e6-96231b3b80d8
Fix tests not to depend on specific regalloc or instruction order.

They were failing with -mcpu=atom.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192890 91177308-0d34-0410-b5e6-96231b3b80d8