wip: try both -Os and -O2 for libstdc++

Author: mhx

.docker/Dockerfile.alpine

@@ -4,7 +4,7 @@ FROM $ARCH/alpine:latest
 
 ARG ARCH
 ARG TARGET_ARCHS
-ARG TOOLCHAIN_OPTIMIZE=2
+ARG TOOLCHAIN_OPTIMIZE=o,2
 
 RUN apk update
 RUN apk upgrade

.docker/build-linux.sh

@@ -290,7 +290,7 @@ if [[ "-$BUILD_TYPE-" == *-shared-* ]]; then
 fi
 
 if [[ "-$BUILD_TYPE-" == *-static-* ]]; then
-  _SYSROOT="/opt/cross/O2"
+  _SYSROOT="/opt/cross/Os"
   _MARCH="${CROSS_ARCH}"
   if [[ -z "$CROSS_ARCH" ]]; then
     _MARCH="${ARCH}"