[ASan] Group all flag parsing code together. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@224087 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] [test] Enable COMPILER_RT_INCLUDE_TESTS for MIPS

Enabling COMPILER_RT_INCLUDE_TESTS and updating tests/sanitizer_allocator_test.cc to remove Allocator64 related tests for MIPS.

Reviewed By: samsonov

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@224101 91177308-0d34-0410-b5e6-96231b3b80d8
Merge branch 'master', remote-tracking branch 'trunk/master'