Enable exceptions in web debug mode

Also optimize for size

Makefile

@@ -46,10 +46,10 @@ CFLAGS_nat_profile := -pg -DNDEBUG $(OMP_FLAG) $(CFLAGS_all)
 
 # Emscripten compiler information
 CXX_web := emcc
-OFLAGS_web_all := $(CXXFLAGS) -Wno-mismatched-tags -Wno-empty-body -s USE_ZLIB=1 -s USE_LIBLZMA=1 -s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall', 'cwrap']" -s TOTAL_MEMORY=671088640 --js-library $(EMP_DIR)/web/library_emp.js -s EXPORTED_FUNCTIONS="['_main', '_empCppCallback', '_empDoCppCallback']" -s DISABLE_EXCEPTION_CATCHING=1 -s NO_EXIT_RUNTIME=1 -s ABORTING_MALLOC=0 -I/usr/lib/x86_64-linux-gnu/openmpi/include/
+OFLAGS_web_all := $(CXXFLAGS) -Wno-mismatched-tags -Wno-empty-body -s USE_ZLIB=1 -s USE_LIBLZMA=1 -s "EXTRA_EXPORTED_RUNTIME_METHODS=['ccall', 'cwrap']" -s TOTAL_MEMORY=671088640 --js-library $(EMP_DIR)/web/library_emp.js -s EXPORTED_FUNCTIONS="['_main', '_empCppCallback', '_empDoCppCallback']" -s NO_EXIT_RUNTIME=1 -s ABORTING_MALLOC=0 -I/usr/lib/x86_64-linux-gnu/openmpi/include/
 OFLAGS_web_pthread := -s USE_PTHREADS=1 -s PROXY_TO_PTHREAD=1
-OFLAGS_web := -O3 -DNDEBUG
-OFLAGS_web_debug := -g4 -Wno-dollar-in-identifier-extension -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=2 -s SAFE_HEAP=1 -s STACK_OVERFLOW_CHECK=2 -D_GLIBCXX_DEBUG -D_LIBCPP_DEBUG
+OFLAGS_web := -O3 -DNDEBUG -s DISABLE_EXCEPTION_CATCHING=1
+OFLAGS_web_debug := -g4 -Oz -Wno-dollar-in-identifier-extension -s DEMANGLE_SUPPORT=1 -s ASSERTIONS=2 -s SAFE_HEAP=1 -s STACK_OVERFLOW_CHECK=2 -D_GLIBCXX_DEBUG -D_LIBCPP_DEBUG -fexceptions
 
 CFLAGS_web := $(CFLAGS_all) $(OFLAGS_web) $(OFLAGS_web_all)
 CFLAGS_web_pthread := $(CFLAGS_all) $(OFLAGS_web) $(OFLAGS_web_pthread) $(OFLAGS_web_all)