Adds a new command line option -mabi= and uses the value to compute
the ABI to use. Adds the ABI to linker and assembler invocation, too.
Allows consistent invocation of the whole tool chain.
The new command line option conflicted with a builtin LLVM 3.0
one. The functionality will be added back in after the 0.11.0
release branch has been created.
This reverts commit 6a1bc70bd7 and
subsequent fixes.
Even though this argument design conflates two separate concepts
(ABI and hardware/software implementation), I chose to go
with it since users are liekly know it from GCC and the
combination of softloat operations with hardfloat ABI makes
no sense.
I didn't implement it for old LLVM versions, as ARM EABI
exception handling requires LLVM 3.3+ anyway, without which
LDC would be useless anyway.
1. Main include corresponding to .cpp file, if any.
2. DMD and LDC includes.
3. LLVM includes.
4. System includes.
Also updated a few include guards to match the default format.
