Fix the problems exposed by the callingconv1.d test case. The first was that unless otherwise specified, inputs are assumed to be in registers even if they specify a "matching output" that's in memory. While testing that fix, I also ran into a bug causing the generated "matching output" for any input was always the first one instead of the correct one.

LLVM D Compiler (LDC)

This compiler is based on the Digital Mars D (DMD) compiler frontend, and
the LLVM compiler toolkit. See LICENSE for licensing information.

For more information, including build instructions, visit the LDC website:

http://www.dsource.org/projects/llvmdc