MC: Cleanup COFFAsmParser::ParseSectionFlags

Switch a normal for-loop to a range-based for. No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212362 91177308-0d34-0410-b5e6-96231b3b80d8
MC: Correct comment in ExportSymbol

No functionality changed, just make it so that the code _could_ be
uncommented.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212363 91177308-0d34-0410-b5e6-96231b3b80d8