cmake mruby msvc: escape compiler command
cmake mruby msvc: escape compiler command

mruby doesn't escape compiler command in CC/CXX implicitly.
We need to escape it if we need. (e.g. CC=C:/Program Files/...)

groonga/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,kenhys/groonga,groonga/groonga,groonga/groonga,kenhys/groonga