[flang] Complex numbers in function arguments on Windows

Function arguments or return values that are complex floating point values
aren't correctly lowered for Windows x86 32-bit and 64-bit targets.
See: https://github.com/llvm/llvm-project/issues/61976

Add targets that are specific for these platforms and OS.

With thanks to @mstorsjo for pointing out the fix.

Reviewed By: vzakhari

Differential Revision: https://reviews.llvm.org/D147768