OCaml 3.10 native-code compiler doesn't build on Mac OS X 10.5.1

["Jeff Meister" <nanaki@gmail.com>]

When attempting to "make opt" on my MacBook Pro running the new
10.5.1, the following error occurs:

gcc -I../byterun -DCAML_NAME_SPACE -DNATIVE_CODE -DTARGET_i386
-DSYS_macosx  -O -Wall -D_FILE_OFFSET_BITS=64 -D_REENTRANT   -c -o
signals_asm.o signals_asm.c
signals_asm.c: In function 'segv_handler':
signals_asm.c:193: error: dereferencing pointer to incomplete type
signals_asm.c:193: error: dereferencing pointer to incomplete type
signals_asm.c: In function 'caml_init_signals':
signals_asm.c:241: error: storage size of 'stk' isn't known
signals_asm.c:241: warning: unused variable 'stk'
make[1]: *** [signals_asm.o] Error 1
make: *** [runtimeopt] Error 2

I'm not sure if OCaml built in the initial Leopard release, 10.5.0,
because I didn't try installing it until after updating to 10.5.1
yesterday... but I do know it worked on 10.4. The bytecode compiler
builds and bootstraps just fine. Any ideas?

Output of gcc -v:

Using built-in specs.
Target: i686-apple-darwin9
Configured with: /var/tmp/gcc/gcc-5465~16/src/configure
--disable-checking -enable-werror --prefix=/usr --mandir=/share/man
--enable-languages=c,objc,c++,obj-c++
--program-transform-name=/^[cg][^.-]*$/s/$/-4.0/
--with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib
--build=i686-apple-darwin9 --with-arch=apple --with-tune=generic
--host=i686-apple-darwin9 --target=i686-apple-darwin9
Thread model: posix
gcc version 4.0.1 (Apple Inc. build 5465)