[dev.typeparams] all: merge dev.regabi (d9acf6f3) into dev.typeparams

Conflicts:

- src/cmd/compile/fmtmap_test.go

Merge List:

+ 2021-01-12 d9acf6f3 [dev.regabi] cmd/compile: remove Func.ClosureType
+ 2021-01-12 41352fd4 [dev.regabi] cmd/compile: transform closures during walk
+ 2021-01-12 d6ad88b4 [dev.regabi] cmd/compile: compile functions before closures
+ 2021-01-12 432f9ffb [dev.regabi] cmd/compile: unindent compileFunctions
+ 2021-01-12 cc90e7a5 [dev.regabi] cmd/compile: always use the compile queue
+ 2021-01-12 cd5b74d2 [dev.regabi] cmd/compile: call NeedFuncSym in InitLSym
+ 2021-01-12 95acd812 [dev.regabi] cmd/compile: remove Name.Typegen
+ 2021-01-12 12ee55ba [dev.regabi] cmd/compile: stop using Vargen for import/export
+ 2021-01-12 b4d2a044 [dev.regabi] cmd/compile: refactor closure var setup/teardown
+ 2021-01-12 f57f4840 [dev.regabi] cmd/compile: decouple escape analysis from Name.Vargen
+ 2021-01-10 7fd84c6e [dev.regabi] cmd/compile: remove OCLOSUREREAD
+ 2021-01-10 c9c26d7f [dev.regabi] cmd/compile: use ClosureVars for method value wrappers
+ 2021-01-10 950cf4d4 [dev.regabi] cmd/compile: bind closure vars during SSA constructions
+ 2021-01-10 8b2efa99 [dev.regabi] cmd/compile: deref PAUTOHEAPs during SSA construction
+ 2021-01-08 6ee9b118 [dev.regabi] cmd/compile: remove fmt_test code; it has outlived its usefulness
+ 2021-01-08 b241938e [dev.regabi] cmd/compile: fix some methods error text

Change-Id: I9a530f9a78b16e2bb14ea0a4ecbd9a75f9350342