[mips] Emit '.set nomicromips' before a function's entry label

[mips] Emit '.set nomicromips' before a function's entry label
if not in micromips mode.

The test (elf_st_other.ll) was renamed as the name and description didn't
make sense as the test wasn't checking any symbol table entry.

Differential Revision: http://reviews.llvm.org/D3346

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206377 91177308-0d34-0410-b5e6-96231b3b80d8