CMake: create AddCompilerRT module and implement convenience add_compiler_rt_object_library function

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@172826 91177308-0d34-0410-b5e6-96231b3b80d8
[sanitizer] Workaround broken mktemp on certain platforms.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@172827 91177308-0d34-0410-b5e6-96231b3b80d8
[ASan] Fix the log_path option to use different log files for parent and child processes after fork().


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@172828 91177308-0d34-0410-b5e6-96231b3b80d8
CMake: Generalize build rules for different arches for sanitizer_common, asan, ubsan

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@172829 91177308-0d34-0410-b5e6-96231b3b80d8