bug 417066. enabling jemalloc by default on linux. r=bsmedberg.

configure.in

@@ -1735,6 +1735,8 @@ case "$target" in
                                       # when using DWARF2 as the debugging
                                       # format)    
 
+    MOZ_MEMORY=1
+
     case "${target_cpu}" in
     alpha*)
     	CFLAGS="$CFLAGS -mieee"

memory/jemalloc/jemalloc.c

@@ -1042,6 +1042,8 @@ const char	*_malloc_options
 = "A10n2F"
 #elif (defined(MOZ_MEMORY_DARWIN))
 = "AP10n"
+#elif (defined(MOZ_MEMORY_LINUX))
+= "A10n2F"
 #endif
 ;