cmd/compile: construct ir.FuncType within typecheck.DeclFunc
Currently all typecheck.DeclFunc callers already construct a fresh new
ir.FuncType, which is the last type expression kind that we represent
in IR.
This CL pushes all of the ir.FuncType construction down into
typecheck.DeclFunc. The next CL will simplify the internals so that we
can get rid of ir.FuncType altogether.
Change-Id: I221ed324f157eb38bb57c8886609f53cc4fd99fe
Reviewed-on: https://go-review.googlesource.com/c/go/+/403848
TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: David Chase <drchase@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>