SERVER-8880 Visual Studio -- remove /OPT:REF and /OPT:ICF

The /OPT:REF (Optimize References) and /OPT:ICF (Enable COMDAT Folding)
Linker flags were set for Release and Win2008PlusRelease builds, which
does not match the link flags set for the scons build.  Remove those
settings to match scons, and to fix the crashes in the SpiderMonkey builds.