Initial configure support for using Clang as the LLVM capable compiler.
Comes in two parts:
1. Use --with-clang=path/to/clang/compiler to select an installed clang, or
--with-built-clang to have the makefiles use the clang which will be built
as the LLVM capable compiler. If neither is given, --with-built-clang will
be used if the Clang sources are checked out into the standard location
(tools/clang).
2. Use --with-llvmcc={llvm-gcc,clang,none} to specify which LLVM capable
compiler to use. If not given, then llvm-gcc will be used if available,
otherwise Clang.
Makefile support still to come.
Eric, Doug, Chris, seem reasonable?
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96934
91177308-0d34-0410-b5e6-
96231b3b80d8