Implement parsing, AST, (de-)serialization, and placeholder global
metadata for linking against the libraries/frameworks for imported
modules.

The module map language is extended with a new "link" directive that
specifies what library or framework to link against when a module is
imported, e.g.,

  link "clangAST"

or

  link framework "MyFramework"

Importing the corresponding module (or any of its submodules) will
eventually link against the named library/framework.

For now, I've added some placeholder global metadata that encodes the
imported libraries/frameworks, so that we can test that this
information gets through to the IR. The format of the data is still
under discussion.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172437 91177308-0d34-0410-b5e6-96231b3b80d8
This patch addresses varargs processing for small complex types under
the 64-bit PowerPC ELF ABI.

The ABI requires that the real and imaginary parts of a complex argument
each occupy their own doubleword.  Arguments smaller than 8 bytes are
right-adjusted within the doubleword.

Clang expects EmitVAARG() to return a pointer to a structure in which
the real and imaginary parts are packed adjacently in memory.  To accomplish
this, we generate code to load the code appropriately from the varargs
location and pack the values into a temporary variable in the form Clang
expects, returning a pointer to that structure.

The test case demonstrates correct code generation for all "small" complex
types on PPC64:  int, short, char, and float.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172438 91177308-0d34-0410-b5e6-96231b3b80d8
Infer "link" lines for top-level frameworks. Essentially, a framework
will have a shared library with the same name as its framework (and no
suffix!) within its .framework directory. Detect this both when
inferring the whole top-level framework and when parsing a module map.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172439 91177308-0d34-0410-b5e6-96231b3b80d8