Only normalize FileSpec paths *after* resolving them.

Normalizing paths before resolving them can cause the path to
become denormalized after resolution.
Link test executables with LLD on Windows.

Clang generates DWARF debug info with section names longer
than 8 characters.  This is only supported by an extension
to PE/COFF which the MSVC linker doesn't implement.  So
trying to link DWARF-enabled object files with MSVC will
lead to corrupt debug information in the executable.
Enable enabling and disabling breakpoints on Windows.
Perform correct lookup when '__super' is used in class with dependent base.