[kaffe] configure command with '-C' option

[Kiyo Inaba]

Hi,

For the last several monthes, kaffe configure command can not handle
'-C' option (to enable using cache for configure) properly. In this
weekend, I finally found some extra time to trace back why it happens.

After checking with several old snapshots, and seeing CVS repository,
I noticed version 1.236 of configure.ac (committed 2006/7/15 by
Dalibor) introduced this problem.

The sympton on this new configure is, if we set -C option to configure,
it tries to pass CFLAGS with its internally generated KAFFE_CFLAGS
with original CFLAGS, but configure itself checkes whether CFLAGS
option passed as an argument to configure command and if it does not
match with CFLAGS stored in config.cache, then error message is
reported (and exit the configuration).

To regenerate this, simply create a directory and configure with -C,
configure command will report when going down to configure in boehm gc
with the error message saying 'error: `CFLAGS' has changed since the
previous run:'.

If I revert the mod committed to the configure.ac (and corresponding
configure), the configure with '-C' option becomes to work.

On the other hand, the commit comment said this mod is needed to
pass KAFFE_CFLAGS options to 'sub-configure invocation'. If this
comment is true, simply revert the change is not the right way to
fix this problem.

Any idea?

This '-C' option for configure is very useful for slooooow machines
like Mac-IIci, for kaffe's regression test.

Kiyo