Work around the unpredictible mangling of int64_t and uint64_t
Add va_list test case
Use correct type for va_list
Merge pull request #3568 from yebblies/valisttype

Use correct type for va_list
Fixed compilation of DMD with MSVC because we keep failing to add new files to the external build system's project files.
Merge pull request #3575 from Orvid/fixvcxprojagain

Fixed compilation of DMD with MSVC
Merge pull request #3574 from yebblies/int64mangle

[DDMD] Work around the unpredictible mangling of int64_t and uint64_t