M4 assembler error on compile

I have run into an issue while compiling M4 1.4.19 for Solaris 7 (per 
GCC's configure, target is "i386-unknown-solaris2.7") using GCC 3.2 and 
Make 4.4. Configuring the source tree goes smoothly, but during the make 
step, the following error is generated (truncated to relevant lines):

make[3]: Entering directory `/staging/stage2/m4-1.4.19/lib`
   CC asyncsafe-spin.o
Assembler: asyncsafe-spin.c
          aline 310        : Illegal mnemonic
          aline 310        : syntax error
make[3]: *** [Makefile:2866: asyncsafe-spin.o] Error 1


I have found no other references to this "aline 310" error at all 
online, so I'm unsure what info is needed to diagnose, or if my build 
environment is even supported in this case, as the only packaged 
versions of most software for Solaris 7 is ancient.

Any assistance is appreciated.