-# (1) We use an abnormal CXX (without library references), so we
-# must cache it under a different name.
-# (2) CC, CFLAGS, CXX, CXXFLAGS, LDFLAGS must not be 'precious', or
-# the non-multilib-adjusted value will be used in multilibs.
-# (3) As a side effect, we must SUBST CXXFLAGS, CFLAGS, and LDFLAGS ourselves.
-# (4) As another side effect, automake doesn't automatically include them
-# in Makefile.in.
-# (5) For libstdc++-v3, -fno-builtin must be present here so that a