Override linker flags for cross compiler

[Pedro Alves <pedro_alves at portugalmail dot pt>]

Hi guys,

I am building for arm-wince-pe target.
I am generating a dll that contains newlib+unix+libstdc++, similar in 
idea to cygwin1.dll
I call this dll cegcc.dll.

Currently, the toolchain makes statically linked executables and dlls, 
and I want
to make it link to cegcc.dll by default.

I've setup gcc specs so that:
gcc/g++ will link to this dll by default.
passing -static to gcc/g++ will remove -lcegcc from the link flags.

I am searching for a way to build the toolchain in one pass without 
depending on having a
prebuilt cegcc.dll.

How can I teach libstdc++ to build with this switch on?

I tried:
crossconfig.m4
 *arm-wince-pe)
+    LIBCFLAGS_FOR_TARGET="-static ${LIBCFLAGS_FOR_TARGET}"
+    AC_SUBST(LIBCFLAGS_FOR_TARGET)

But didn't work.
The autotests for a working compiler, executable suffix, etc, will fail,
because that "-static" isn't showing anywhere, and there is no 
libcegcc.a yet.

Any hints?

Cheers,
Pedro Alves