Adjust the IRGen for ObjC interop to ensure that the section that
metadata is emitted into the correct section for non-MachO targets.
This also adds a more comprehensive test for ensuring that the IRGen can
now be tested on all targets. Since the ObjC interop is now
controllable via the driver, this test does not require that the
objc_interop feature is present as it is a IRGen test.
This is the first step to remove the `REQUIRES: objc_interop` from the
IRGen tests.
When lowering the arguments for the FFI call on certain targets, LLVM
expects that the parameter be passed as a structure rather than the
extracted values. Enhance the argument lowering for the call and the
function construction to ensure that the type can be flattened according
to the ABI for the target before attempting to explode it for the SIL
IRGen lowering. This allows building for targets such as Linux ARM HF
and Linux ARM SF target with the HF floating point ABI.
Addresses SR-6142!
Sema was dutifully tracking conformances that were "used" as part of
type checking, so it could make sure that those conformances got
completed for SILGen to use. However, this information never actually
made it to SILGen, which included its own (more conservative, not
broad enough) heuristics for finding "used" conformances. Teach Sema
to record conformances within the appropriate source file, and have
SILGen reference the conformances when it emits SIL for the source
file.
The interesting thing here is that we need runtime support in
order to generate references to metatypes for classes, mostly
because normal ObjC classes don't have all the information we want
in a metatype (which for now just means the VWT pointer).
We'll need to be able to reverse this mapping when finding a
class pointer to hand off to, say, an Objective-C class method,
of course.
Swift SVN r3424