When combining the code-completion results from Sema long with the

When combining the code-completion results from Sema long with the
code-completion results cached by ASTUnit, sort the resulting result
set. This makes testing far, far easier, so this commit also includes
tests for the previous few fixes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112070 91177308-0d34-0410-b5e6-96231b3b80d8