Thanks for looking into this, Bruno.
I had one other problem on the same solaris machine, after applying
your previous patch (which btw seems to be working OK):
gcc -W -Wswitch -Wcomment -Wpointer-arith -Wimplicit -Wreturn-type -Wno-sign-compare -O2 -fno-schedule-insns -fno-gcse -DUNIX_BINARY_DISTRIB -DUNICODE -DDYNAMIC_FFI -DDYNAMIC_MODULES -DNO_GETTEXT -DNO_SIGSEGV -I. -fPIC -I../ -c regexi.m.c -o regexi.o
In file included from regexi.c:7:
../clisp.h:560: parse error before `saved_back_trace'
../clisp.h:560: warning: type defaults to `int' in declaration of `saved_back_trace'
../clisp.h:560: warning: data definition has no type or storage class
../clisp.h:3511: warning: call-clobbered register used for global register variable
I moved the definition of saved_back_trace below the p_backtrace_t
struct definition in clisp.h, which seemed to work.