Renaming header guards to match the LLVM convention.
This patch was created by automatically applying the fixes from
clang-tidy.
I've removed the [NFC] tag from the title, as we're adding header guards in some files and thus might trigger behavior changes.
Differential Revision: https://reviews.llvm.org/D113896
The patch also does some cleanup on the interface of the entry
points from TargetFinder into the heuristic resolution code.
Since the heuristic resolver is created in a place where the
ASTContext is available, it can store the ASTContext and the
NameFactory hack can be removed.
Differential revision: https://reviews.llvm.org/D92290