- This change implements the correct type-based equivalence
relation for aggregate types. e.g. comparison of struct
types no longer compares the anonymous fields. We do
analogous things for hash().
- equals() and eqnil() have been separated: the former panics
for uncomparable types, the latter permits comparisons of
slice/map/func types against a literal nil and is intended
for use only by "static" ssa.BinOp(EQL), not "dynamic" slice
comparisons encountered during (e.g.) interface comparisons,
which should panic regardless of operand nilness.
- we use a (global) typemap.Hasher to compute type hashes;
hashing the Type.String() value was not sound.
+ tests.
NB, this change unearthed a bug in defer/recover within
init(); it will be fixed in a followup change.
R=gri, crawshaw
CC=golang-dev
https://golang.org/cl/13719043
5db6491e90