Implement D calling convention

float, double, real, cfloat, cdouble and creal ABI should be correct for the most part now. At leasts returning them on the x87 FPU stack on x86 is implemented now.

dynamic arrays are handled properly since [715]

delegates now follow ABI as well

First param (except structs that would fit) are no passed in EAX on x86-32 since rev [720]

Only thing missing now is passing arguments formal in the correct (opposite of now) order, and handle the cases where struct are passed/returned in EAX

Parameter order should be correct for x86-32 since rev [723]

only struct in registers missing now :)

struct return convention is only specified for Windows now, this means we're only missing small structs in registers. At least as long as Windows isn't supported :)

since rev [930] the appropriate struct in passed inreg, but it looks like llvm doesn't always pass it in a reg regardless :/ this is unfortunate. I think we might need to manually convert it to a i32 or something like that to be sure.

I tried it with 1, 2 and 4 byte structs and they were passed in a register. Can you give me your test case?

Should be fixed in [938]