[Sanitizer] Get rid of unnecessary allocations in StripModuleName. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@221287 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] [mips] changed ShadowOffset32 for systems having 16kb PageSize; patch by Kumar Sukhani

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@221288 91177308-0d34-0410-b5e6-96231b3b80d8