Use strings instead of TableGen defs in the compilation graph
definition. Makes it easier for the plugins to modify an existing graph.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59447 91177308-0d34-0410-b5e6-96231b3b80d8
Plugins can be now compiled in with a slight Makefile change.
For example, to compile the new Clang driver, use:
cd $LLVMC2_DIR
make TOOLNAME=ccc2 BUILTIN_PLUGINS=Clang
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56967 91177308-0d34-0410-b5e6-96231b3b80d8
