Fix copy/paste to refer to the relevant type (ProgramPoint instead of TypeLoc).

Post commit review feedback on r175812 from Jordan Rose.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175825 91177308-0d34-0410-b5e6-96231b3b80d8
Simplify code to use castAs rather than getAs + assert.

Post commit review feedback on r175812 from Jordan Rose.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175826 91177308-0d34-0410-b5e6-96231b3b80d8