Drop the size arguments for the hash/equal functions stored in type
descriptors. Types know what size they are. To make this work,
generate hash/equal functions for types that can use an identity
comparison but are not a standard size and alignment.
Drop the multiplications by 33 in the generated hash code and the
reflect package hash code. They are not necessary since we started
passing a seed value around, as the seed includes the hash of the
earlier values.
Copy the algorithms for standard types from the Go 1.7 runtime,
replacing the C functions.
Reviewed-on: https://go-review.googlesource.com/34983
From-SVN: r244256
0c22e4415f