* some SDL functions from SDL1.x and SDL2.x
update test_safe_dyncalls
refactor mouse wheel handling code to be shared across SDL, glfw, glut
Merge branch 'incoming' of github.com:mgerhardy/emscripten into incoming

Conflicts:
	src/library_sdl.js
Implement SDL audio buffer queueing to use Web Audio ScriptProcessorNode in the special case when the requested SDL_OpenAudio sampling rate matches the Web Audio graph native sampling rate. Using ScriptProcessorNode should have the benefit that it pulls audio buffer updates with better granularity/precision than using setTimeout, which suffers from too much jitter (even spikes as long as 230msecs seen).
Merge pull request #2117 from juj/scriptprocessornode

Implement SDL audio buffer queueing to use Web Audio ScriptProcessorNode.
optimize redundant frounds in -O3
silly little llvm debug tool
improve logging of opts
add longjmp testcase for keeping stuff together and in proper dominance order
Merge branch 'incoming' of https://github.com/kripken/emscripten into incoming