Fix the unexec build on GNU/Linux

The unexec build on GNU/Linux must use HYBRID_MALLOC (gmalloc.c) and
sheap.c.  This was inadvertently disabled because a configure-time
test for 'sbrk' was moved as side effect of an unrelated change.

* configure.ac: Test for 'sbrk' before using the result in the
decision about SYSTEM_MALLOC and HYBRID_MALLOC.
(HYBRID_MALLOC): Prevent Gnulib from redirecting 'free' to its
replacement 'rpl_free'.

* lib/Makefile.in (not_emacs_OBJECTS): Add mallooc/%.o and free.o.

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/Makefile.in b/lib/Makefile.in
index 6c7a4430999..ec92f92fb3e 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -69,7 +69,9 @@ Makefile: ../config.status $(srcdir)/Makefile.in
 # Object modules that need not be built for Emacs.
 # Emacs does not need e-regex.o (it has its own regex-emacs.c),
 # and building it would just waste time.
-not_emacs_OBJECTS = regex.o
+# Emacs also doesn't need the dynarray-related files in malloc/ and
+# the replacement 'free'.
+not_emacs_OBJECTS = regex.o malloc/%.o free.o
 
 libgnu_a_OBJECTS = fingerprint.o $(gl_LIBOBJS) \
   $(patsubst %.c,%.o,$(filter %.c,$(libgnu_a_SOURCES)))