[analyzer] Fix typo, better doxygen as per Jordan's feedback.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174434 91177308-0d34-0410-b5e6-96231b3b80d8
[analyzer] add comment

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174435 91177308-0d34-0410-b5e6-96231b3b80d8
[analyzer] Teach the analyzer to use a symbol for p when evaluating
(void*)p.

Addresses the false positives similar to the test case.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174436 91177308-0d34-0410-b5e6-96231b3b80d8