Takes the SIMD runtime intrinsics as a starting point for defining TF machine operators. The rationale for omitting functions is:

 - Check functions.
 - 'FromXxxBits' functions. These are essentially casts.
 - UInt constructors. int and uint aren't distinguished in wasm.
 - Uint functions, except where their behavior is bitwise different from the Int function.

Some operators are typeless, i.e. they are the same for multiple related types, e.g. logical ops for int types, load/store for float and int types. Use a 'Simd128' prefix for these operators.

Skipped fns:

Float32x4Check
Float32x4FromInt32x4Bits
Float32x4FromUint32x4Bits
Float32x4FromInt16x8Bits
Float32x4FromUint16x8Bits
Float32x4FromInt8x16Bits
Float32x4FromUint8x16Bits

Int32x4Check
Int32x4FromUint32x4
Int32x4FromFloat32x4Bits
Int32x4FromUint32x4Bits
Int32x4FromInt16x8Bits
Int32x4FromUint16x8Bits
Int32x4FromInt8x16Bits
Int32x4FromUint8x16Bits

CreateUint32x4
Uint32x4Check
Uint32x4ExtractLane
Uint32x4ReplaceLane
Uint32x4Add
Uint32x4Sub
Uint32x4Mul
Uint32x4And
Uint32x4Or
Uint32x4Xor
Uint32x4Not
Uint32x4Equal
Uint32x4NotEqual
Uint32x4Select
Uint32x4Swizzle
Uint32x4Shuffle
Uint32x4FromInt32x4
Uint32x4FromFloat32x4Bits
Uint32x4FromInt32x4Bits
Uint32x4FromInt16x8Bits
Uint32x4FromUint16x8Bits
Uint32x4FromInt8x16Bits
Uint32x4FromUint8x16Bits

Bool32x4Check

Int16x8Check
Int16x8FromUint16x8
Int16x8FromFloat32x4Bits
Int16x8FromInt32x4Bits
Int16x8FromUint32x4Bits
Int16x8FromUint16x8Bits
Int16x8FromInt8x16Bits
Int16x8FromUint8x16Bits

CreateUint16x8
Uint16x8Check
Uint16x8ExtractLane
Uint16x8ReplaceLane
Uint16x8Add
Uint16x8Sub
Uint16x8Mul
Uint16x8And
Uint16x8Or
Uint16x8Xor
Uint16x8Not
Uint16x8Equal
Uint16x8NotEqual
Uint16x8Select
Uint16x8Swizzle
Uint16x8Shuffle
Uint16x8FromInt16x8
Uint16x8FromFloat32x4Bits
Uint16x8FromInt32x4Bits
Uint16x8FromUint32x4Bits
Uint16x8FromInt16x8Bits
Uint16x8FromInt8x16Bits
Uint16x8FromUint8x16Bits

Bool16x8Check

Int8x16Check
Int8x16FromUint8x16
Int8x16FromFloat32x4Bits
Int8x16FromInt32x4Bits
Int8x16FromUint32x4Bits
Int8x16FromInt16x8Bits
Int8x16FromUint16x8Bits
Int8x16FromUint8x16Bits

CreateUint8x16
Uint8x16Check
Uint8x16ExtractLane
Uint8x16ReplaceLane
Uint8x16Add
Uint8x16Sub
Uint8x16Mul
Uint8x16And
Uint8x16Or
Uint8x16Xor
Uint8x16Not
Uint8x16Equal
Uint8x16NotEqual
Uint8x16Select
Uint8x16Swizzle
Uint8x16Shuffle
Uint8x16FromInt8x16
Uint8x16FromFloat32x4Bits
Uint8x16FromInt32x4Bits
Uint8x16FromUint32x4Bits
Uint8x16FromInt16x8Bits
Uint8x16FromUint16x8Bits
Uint8x16FromInt8x16Bits

Bool8x16Check

Generic operators for Float, Int types:

Simd128Load
Simd128Load1
Simd128Load2
Simd128Load3
Simd128Store
Simd128Store1
Simd128Store2
Simd128Store3

Generic operators for Int types:

Simd128And
Simd128Or
Simd128Xor
Simd128Not

LOG=N
BUG=v8:4124

Committed: https://crrev.com/3831d41e4ce7b162775732cb6ac1f8139e60aa30
Cr-Commit-Position: refs/heads/master@{#35213}

Review-Url: https://codereview.chromium.org/1848433003
Cr-Commit-Position: refs/heads/master@{#35951}