Reapply Support layering fixes.
Compiler.h is used by Demangle (which Support depends on) - so sink it
into Demangle to avoid a circular dependency
DataTypes.h is used by llvm-c (which Support depends on) - so sink it
into llvm-c.
DataTypes.h could probably be fixed the other way - making llvm-c depend
on Support instead of Support depending on llvm-c - if anyone feels
that's the better option, happy to work with them on that.
I /think/ this'll address the layering issues that previous attempts to
commit this have triggered in the Modules buildbot, but I haven't been
able to reproduce that build so can't say for sure. If anyone's having
trouble with this - it might be worth taking a look to see if there's a
quick fix/something small I missed rather than revert, but no worries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@328123
91177308-0d34-0410-b5e6-
96231b3b80d8