In some build configurations a warning about (an absolute path for)
-fuse-ld= not being supported by GCC was emitted during cleandir or
other non-build make targets.
For these non-build targets COMPILER_TYPE is set to "none" but we
treated the .else case for COMPILER_TYPE==clang as implying gcc.
Check instead for COMPILER_TYPE==gcc.
PR: 263913
Reported by: pstef
Reviewed by: pstef
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
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