This patch deprecates `module.map` in favor of `module.modulemap`, which
has been the preferred form since 2014. The eventual goal is to remove
support for `module.map` to reduce the number of stats Clang needs to do
while searching for module map files.
This patch touches a lot of files, but the majority of them are just
renaming tests or references to the file in comments or documentation.
The relevant files are:
* lib/Lex/HeaderSearch.cpp
* include/clang/Basic/DiagnosticGroups.td
* include/clang/Basic/DiagnosticLexKinds.td
Module map files provide a way to map between headers and modules, so
that we can layer a module system on top of existing headers without
changing those headers at all.
This commit introduces the module map file parser and the module map
that it generates, and wires up the module map file parser so that
we'll automatically find module map files as part of header
search. Note that we don't yet use the information stored in the
module map.
llvm-svn: 144402
