Add a MangleContext and pass it to all mangle functions. It will be used for keeping state, such as identifiers assigned to anonymous structs as well as scope encoding.

llvm-svn: 83442

llvm-svn: 81585

llvm-svn: 81346

llvm-svn: 81143

offsets better for thunk refinements.  Cleanups.  WIP.

llvm-svn: 81067

llvm-svn: 80747

llvm-svn: 80744

llvm-svn: 80743

llvm-svn: 77751

llvm-svn: 77699

llvm-svn: 69343

llvm-svn: 69150

llvm-svn: 68969

1. it wasn't applying to definitions, only declarations, e.g. int x __asm("foo")
2. multiple definitions were conflicting, they weren't getting merged.
3. the code was duplicated in several places.

llvm-svn: 67442

llvm-svn: 64984

ABI to the CodeGen library. Since C++ code-generation is so
incomplete, we can't exercise much of this mangling code. However, a
few smoke tests show that it's doing the same thing as GCC. When C++
codegen matures, we'll extend the ABI tester to verify name-mangling
as well, and complete the implementation here.

At this point, the major client of name mangling is in the uses of the
new "overloadable" attribute in C, which allows overloading. Any
"overloadable" function in C (or in an extern "C" block in C++) will
be mangled the same way that the corresponding C++ function would be
mangled.

llvm-svn: 64413