Does gdb/configure ignore --with-gmp?

[Stephen Casner]

Following up on this part of my test results for Nick Alcock's fix:

> With the following configure:
>
> auge6> ~/src/gnu/binutils-gdb/configure --prefix=/usr/local --with-gmp=/opt/local
>
> It builds through gdbsupport, but I have an unrelated problem with gdb
> configure:
>
> checking for libgmp... no
> configure: error: GMP is missing or unusable
>
> This even though I have the --with-gmp and /usr/local/lib/libgmp.*
> exist.  I need to investigate that further.

The error is that gmp.h is not found when compiling conftest.  But the
compile command does not include -I/usr/local/include which it should,
based on the configure option.  Is that a bug in gdb/configure.ac?
The option did get passed to gdb/configure as shown in gdb/config.log.

                                                        -- Steve