This dates back to the creation of top-level `libgcc` in
fa9585134f6f58fa0d3da3ca4ad5493855aea2dc. I strongly suspect that this
does nothing.
Andrew Pinksi adds:
> So looking into this further, MACHMODE_H used part of LIBGCC_DEPS
> because of TM_H and
r0-78222-gfa9585134f6f58 moved away from including
> tm.h from libgcc. It was copied over unused.
It is indeed used then.
(For background context, my overall goal here is hoping libgcc can depend on
fewer/no stuff that is generated by `gcc/Makefile`. This is me trying to
pluck some low-hanging fruit -- this is the only direct mention of
`insn-modes.h` in libgcc.)
libgcc/ChangeLog:
* Makefile.in: Delete dead `MACHMODE_H` variable
GCC_FOR_TARGET = $(CC)
LIPO = @LIPO@
LIPO_FOR_TARGET = $(LIPO)
-MACHMODE_H = machmode.h mode-classes.def insn-modes.h
NM = @NM@
NM_FOR_TARGET = $(NM)
RANLIB_FOR_TARGET = $(RANLIB)
export LIB1ASMSRC
export LIBGCC2_CFLAGS
export LIPO_FOR_TARGET
-export MACHMODE_H
export NM_FOR_TARGET
export STRIP_FOR_TARGET
export RANLIB_FOR_TARGET