Enabled relaxed LiveVariables analysis in the path-sensitive engine to...

Enabled relaxed LiveVariables analysis in the path-sensitive engine to increase the coverage of bugs. Primarily affects IdempotentOperationChecker.
- Migrated a temporarily separated test back to its original file (bug has been fixed, null-deref-ps-temp.c -> null-deref-ps.c)
- Changed SymbolManager to use relaxed LiveVariables
- Updated several test cases that the IdempotentOperationChecker class now flags
- Added test case to test relaxed LiveVariables use by the IdempotentOperationChecker

llvm-svn: 112312