[dev.typeparams] cmd/compile: fix missing sync implicit types

CL 328051 introduced new syncImplicitTypes, but forgot to add a sync
after syncAddBody in linker.relocFuncExt, cause the compiler crashes
when reading in package data.

Adding missing w.sync(syncImplicitTypes) call fixes this.

While at it, also run go generate to update code generated for
syncImplicitTypes, which is also missed in CL 328051.

Change-Id: Ic65092f69f8d8e63de15989c7f15b6e5633d8f9e
Reviewed-on: https://go-review.googlesource.com/c/go/+/328054


Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Go Bot <gobot@golang.org>