Update the simd.js (14aa231 -> 248545e)

API Change:
e38d8a9 Add SIMD types load and store opertaions
90570b9 Add the SIMD types support into DataView interface.
fc7927f Handle negative zero in float32x4 and float64x2 signMask getter
Add SIMD test case (simd_test7) for negative zero handling.
add mouse enter/leave events
Apply comment to HTML5 key event 'which' field to help developers not shy away from it, since it currently has the best cross-browser support. Fixes #2817.
document more js library stuff
Fix NaN and -0.0 aware _mm_min_ps and _mm_max_ps implementations, due to a typo, max was min and vice versa.
do not track eliminatable variables from inside a switch to outside
fix _tmpfile to allocate mode argument correctly
windowHint isn't a wrapped function.

The implementation is simple hints assignment, so just implement without
wrapping. Also adds test in test_glfw.c that tests this.
Merge pull request #2830 from Cloudef/incoming-glfw3-window-hint

windowHint isn't a wrapped function.
Merge pull request #2815 from huningxin/incoming

Update SIMD.js polyfill and add test case for negative zero handling.
Asm.js validation for SIMD
Merge pull request #2826 from sunfishcode/incoming

Asm.js validation for SIMD
disable simd tests in old compiler
Add more SIMD API functions.
fix contributing link
add EMCC_JSOPT_BLACKLIST env var; fixes #2819
SIMD header file updates

Add more xmmintrin.h shuffle function wrappers, add attributes nothrow and
const to the emscripten API functions, and general tidying.
Fix minor user namespace incursions.
Make vector typedefs may_alias.

This avoids ambiguities in the C type-based aliasing rules when loading
from arrays of float using float32x4 types.