runsuite_common_pre mangles non-VS paths, messing up WiX

Dr. Memory uses WiX to build its installer and its path is mangled by runsuite_common_pre.cmake: C:\Program Files (x86)\WiX Toolset v3.11\bin => C:\Program Files (x86)\WiX Toolset v3.11\bin\x64

The code looks for a "v" trying to match SDKs/Windows/v{6.0A,7.0}:

          string(REGEX REPLACE "(v[^/\\\\]*)([/\\\\])([Bb][Ii][Nn])" "\\1\\2\\3\\2x64"
            newpath "${newpath}")

For now Dr. Memory is computing the 8.3 path and using that instead as a workaround.