[Sanitizer tests] Don't need to use -lstdc++ thanks to --driver-mode=g++

Reviewed at http://reviews.llvm.org/D3796

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209115 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] update asan_symbolize.py to use the new llvm-symbolizer flag syntax

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@209116 91177308-0d34-0410-b5e6-96231b3b80d8