configure: add --enable-small

Build with -O2 rather than -O3, to dissuade the compiler from inlining
so much. See issue #1.

Change-Id: Iacb8ddb59125d3f01c5fea846b45a1c004c9aee0

build/make/configure.sh

@@ -880,9 +880,9 @@ process_common_toolchain() {
     enabled gcov &&
         check_add_cflags -fprofile-arcs -ftest-coverage &&
         check_add_ldflags -fprofile-arcs -ftest-coverage
-    enabled optimizations && check_add_cflags -O3
-    if enabled rvct; then
-        enabled optimizations && check_add_cflags -Otime
+    if enabled optimizations; then
+        enabled rvct && check_add_cflags -Otime
+        enabled small && check_add_cflags -O2 || check_add_cflags -O3
     fi
 
     # Position Independant Code (PIC) support, for building relocatable

configure

@@ -38,6 +38,7 @@ Advanced options:
   ${toggle_realtime_only}         enable this option while building for real-time encoding
   ${toggle_runtime_cpu_detect}    runtime cpu detection
   ${toggle_shared}                shared library support
+  ${toggle_small}                 favor smaller size over speed
   ${toggle_arm_asm_detok}         assembly version of the detokenizer (ARM platforms only)
 
 Codecs:
@@ -244,6 +245,7 @@ CONFIG_LIST="
     spatial_resampling
     realtime_only
     shared
+    small
     arm_asm_detok
 "
 CMDLINE_SELECT="
@@ -281,6 +283,7 @@ CMDLINE_SELECT="
     spatial_resampling
     realtime_only
     shared
+    small
     arm_asm_detok
 "