main/luajit: build with -O2 instead of -Os

This will increase the size of the luajit package (unpacked) from
1108 kiB to 1340 kiB.

main/luajit/APKBUILD

@@ -4,7 +4,7 @@ pkgname=luajit
 _pkgname=luajit2
 pkgver=2.1_p20210510
 _pkgver=${pkgver/_p/-}
-pkgrel=2
+pkgrel=3
 _gitrev_tests=485311ff265763c2aecce155ad697a974838857c
 pkgdesc="OpenResty's branch of LuaJIT"
 url="https://github.com/openresty/luajit2"
@@ -49,6 +49,10 @@ prepare() {
 }
 
 build() {
+	# It's a language runtime, performance does matter. Users for whom disk
+	# size is more important can use lua5.1 instead.
+	export CFLAGS="${CFLAGS/-Os/-O2}"
+
 	# These flags are recommended by OpenResty.
 	local xcflags="-DLUAJIT_ENABLE_LUA52COMPAT -DLUAJIT_NUMMODE=2"