[release-branch.go1.1] cmd/gc: fix issue with method wrappers not having...

[release-branch.go1.1] cmd/gc: fix issue with method wrappers not having escape analysis run on them.

««« CL 10383048 / 58e15340e78f
cmd/gc: fix issue with method wrappers not having escape analysis run on them.

Escape analysis needs the right curfn value on a dclfunc node, otherwise it will not analyze the function.
When generating method value wrappers, we forgot to set the curfn correctly.

Fixes #5753.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10383048
»»»

Update #5928

R=golang-dev, dave
CC=golang-dev
https://golang.org/cl/11669043