Merge pull request #76 from sunfishcode/master

Minor fixes and simplifications
Implement new min/max semantics

Following the proposal in
https://github.com/johnmccutchan/ecmascript_simd/issues/67

These min and max functions follow the Math.min and Math.max semantics,
and are arguably the more intuitive and semantics.

This patch also introduces minNum and maxNum functions, which follow the
IEEE-754 minNum and maxNum semantics.
Add tests for minNum and maxNum.
Don't use floor for float-to-int conversion

The default rounding for float-to-int conversion should be truncation,
rather than floor.
Use consistent coercion in constructors

Make the SIMD constructors convert their scalar operands to their
desired types.
Simplify constructor coersion

Use |0 instead of a function which does conversion to int32 using a typed
array, and use Math.fround when available for converstion to float32.
Tests for floating-point comparisons.
Tests for integer comparisons.
Additional tests for abs, neg, and div
Merge pull request #80 from sunfishcode/minmax

Implement new min/max semantics
Merge pull request #88 from sunfishcode/tests

Miscelaneous tests
Merge pull request #82 from sunfishcode/ctors

Fixes and tests for constructor functions
Fix support for unaligned loads and stores

This patch reverts 42ea326b24d35a8e3036bd6e7c91ed4b522e9dd3, since broke
handling of misaligned loads and stores, and adds tests for unaligned
loads and stores.
Initial int16x8 and int8x16 support

https://github.com/johnmccutchan/ecmascript_simd/issues/75
fromInt16x8Bits and fromInt8x16Bits conversions
int16x8 and int8x16 constructors
int8x16 and int16x8 arithmetic
int16x8 and int8x16 load and store
Integer !=, >=, and <=

https://github.com/johnmccutchan/ecmascript_simd/issues/46
Unsigned integer comparisons