Change Emscripten optimization level

Makefile

@@ -99,7 +99,7 @@ ifneq (,$(strip $(findstring $(TARGETTYPE), WebAssembly)))
 	# Emscripten optimization documentation
 	# - https://emscripten.org/docs/optimizing/Optimizing-Code.html#optimizing-code
 	# - https://emscripten.org/docs/tools_reference/emcc.html#emcc-compiler-optimization-options
-  	CFLAGS += -Os
+  	CFLAGS += -O2
 
 	# Documentation for various Emscripten flags
 	# - Full List:    https://github.com/emscripten-core/emscripten/blob/main/src/settings.js