[dev.typeparams] all: merge dev.regabi into dev.typeparams

The files below had conflicts that required manual resolution.
The unresolved conflict in noder.go was just in the import
declaration (trivial). All the other conflicts are in tests
where the ERROR regex patterns changed to accomodate gccgo
error messages (incoming from dev.regabi), and to accomodate
types2 in dev.typeparams. They were resolved by accepting the
dev.regabi changes (so as not to lose them) and then by re-
applying whatever changes needed to make them pass with types2.
Finally, the new test mainsig.go was excluded from run.go when
using types2 due to issue #43308.

	src/cmd/compile/internal/gc/noder.go
	test/fixedbugs/bug13343.go
	test/fixedbugs/bug462.go
	test/fixedbugs/issue10975.go
	test/fixedbugs/issue11326.go
	test/fixedbugs/issue11361.go
	test/fixedbugs/issue11371.go
	test/fixedbugs/issue11674.go
	test/fixedbugs/issue13365.go
	test/fixedbugs/issue13471.go
	test/fixedbugs/issue14136.go
	test/fixedbugs/issue14321.go
	test/fixedbugs/issue14729.go
	test/fixedbugs/issue15898.go
	test/fixedbugs/issue16439.go
	test/fixedbugs/issue17588.go
	test/fixedbugs/issue19323.go
	test/fixedbugs/issue19482.go
	test/fixedbugs/issue19880.go
	test/fixedbugs/issue20185.go
	test/fixedbugs/issue20227.go
	test/fixedbugs/issue20415.go
	test/fixedbugs/issue20749.go
	test/fixedbugs/issue22794.go
	test/fixedbugs/issue22822.go
	test/fixedbugs/issue22921.go
	test/fixedbugs/issue23823.go
	test/fixedbugs/issue25727.go
	test/fixedbugs/issue26616.go
	test/fixedbugs/issue28079c.go
	test/fixedbugs/issue28450.go
	test/fixedbugs/issue30085.go
	test/fixedbugs/issue30087.go
	test/fixedbugs/issue35291.go
	test/fixedbugs/issue38745.go
	test/fixedbugs/issue41247.go
	test/fixedbugs/issue41440.go
	test/fixedbugs/issue41500.go
	test/fixedbugs/issue4215.go
	test/fixedbugs/issue6402.go
	test/fixedbugs/issue6772.go
	test/fixedbugs/issue7129.go
	test/fixedbugs/issue7150.go
	test/fixedbugs/issue7153.go
	test/fixedbugs/issue7310.go
	test/fixedbugs/issue8183.go
	test/fixedbugs/issue8385.go
	test/fixedbugs/issue8438.go
	test/fixedbugs/issue8440.go
	test/fixedbugs/issue8507.go
	test/fixedbugs/issue9370.go
	test/fixedbugs/issue9521.go

Change-Id: I26e6e326fde6e3fca5400711a253834d710ab7f4

test/fixedbugs/issue25727.go

@@ -9,13 +9,13 @@ package main
 import "net/http"
 
 var s = http.Server{}
-var _ = s.doneChan                  // ERROR "s.doneChan undefined .cannot refer to unexported field or method doneChan.$|s.doneChan undefined"
-var _ = s.DoneChan                  // ERROR "s.DoneChan undefined .type http.Server has no field or method DoneChan.$"
-var _ = http.Server{tlsConfig: nil} // ERROR "unknown field 'tlsConfig' in struct literal.+ .but does have TLSConfig.$|unknown field 'tlsConfig'"
-var _ = http.Server{DoneChan: nil}  // ERROR "unknown field 'DoneChan' in struct literal of type http.Server$"
+var _ = s.doneChan                  // ERROR "s.doneChan undefined .cannot refer to unexported field or method doneChan.$|unexported field or method|s.doneChan undefined"
+var _ = s.DoneChan                  // ERROR "s.DoneChan undefined .type http.Server has no field or method DoneChan.$|undefined field or method"
+var _ = http.Server{tlsConfig: nil} // ERROR "unknown field 'tlsConfig' in struct literal.+ .but does have TLSConfig.$|unknown field .?tlsConfig.? in .?http.Server|unknown field"
+var _ = http.Server{DoneChan: nil}  // ERROR "unknown field 'DoneChan' in struct literal of type http.Server$|unknown field .?DoneChan.? in .?http.Server"
 
 type foo struct {
 	bar int
 }
 
-var _ = &foo{bAr: 10} // ERROR "unknown field 'bAr' in struct literal.+ .but does have bar.$|unknown field 'bAr'"
+var _ = &foo{bAr: 10} // ERROR "unknown field 'bAr' in struct literal.+ .but does have bar.$|unknown field .?bAr.? in .?foo|unknown field"