<rdar://problem/12069589>

Fixed an issue where not all text would always be seen when running any of the functions in heap.py in Xcode. Now we put the text directly into the command result object and skip STDIO since we have issues with STDIO right now in python scripts.

Also fixed an issue with the "--stack-history" option where MallocStackLoggingNoCompact was assumed to have to be enabled... It doesn't, just MallocStackLogging.

llvm-svn: 163042