example_emscripten: BINARYEN_TRAP_MODE is not supported

[podsvirov]

I tried to build an example_emscripten example using provided Makefile file, but got an error:

$ make
em++ -I../ -I../../ -Wall -Wformat -Os -s USE_SDL=2 -s WASM=1 -s ALLOW_MEMORY_GROWTH=1 -s BINARYEN_TRAP_MODE=clamp -s DISABLE_EXCEPTION_CATCHING=1 -s NO_EXIT_RUNTIME=0 -s ASSERTIONS=1  -c -o main.o main.cpp
shared:ERROR: BINARYEN_TRAP_MODE is not supported by the LLVM wasm backend
make: *** [Makefile:43: main.o] Error 1

Maybe we just need to remove the -s BINARYEN_TRAP_MODE=clamp option?

Cc: @ocornut @nicolasnoble @Funto

[ocornut]

cc @floooh who may know.

[podsvirov]

In #1713 PR, I am perfectly able to compile this example with only one option: -s USE_SDL=2.

[floooh]

Emscripten has switched to the "official" LLVM WASM backend a couple of days ago (with emscripten version 1.39.0), any older SDK still needs BINARYEN_TRAP_MODE flag, but when compiling with a newer SDK, the flag needs to be removed.

Here's the announcement: https://groups.google.com/forum/#!topic/emscripten-discuss/NpxVAOirSl4.

Looks like the switch didn't go completely smoothly, but with Dear ImGui I only had to remove this TRAP_MODE flag in my build system files.

PS @podsvirov: IFIR the missing flag didn't cause compilation errors or crashes in older emscripten versions, but subtle rendering errors (like missing or messed up text).

[ocornut]

What a mess :(
Merged, thank you.!