[ELF][MIPS] Use section type to recognize .reginfo and .MIPS.options sections
[ELF][MIPS] Use section type to recognize .reginfo and .MIPS.options sections

It is faster and more correct method than string comparision.

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@276807 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld