retrieve path to the Microsoft compiler executable
retrieve the name of the default C runtime library
get the path to the Windows SDK CRT libraries
get the path to the universal CRT libraries
get Visual C bin folder
get Visual C Library folder
fill member variables from environment or registry
retrieve options to be passed to the Microsoft linker
retrieve path to the Microsoft linker executable also modifies PATH environment variable if necessary to find conditionally loaded DLLs
set all members to null. Used if we detect a VS installation but end up falling back on lld-link.exe