cmd/go: update out of date help text about vendoring

Change-Id: I2b61f3b3ecf28d8f6a8dff94d194b6d3d450ea22
Reviewed-on: https://go-review.googlesource.com/17996Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>

src/cmd/go/alldocs.go

@@ -1019,9 +1019,6 @@ As of Go 1.6 they are on by default. To turn them off, set
 GO15VENDOREXPERIMENT=0. In Go 1.7, the environment
 variable will stop having any effect.
 
-The vendoring semantics are an experiment, and they may change
-in future releases. Once settled, they will be on by default.
-
 See https://golang.org/s/go15vendor for details.
 
 
@@ -1089,7 +1086,7 @@ Special-purpose environment variables:
 		File names in stack traces are rewritten from GOROOT to
 		GOROOT_FINAL.
 	GO15VENDOREXPERIMENT
-		Set to 1 to enable the Go 1.5 vendoring experiment.
+		Set to 0 to disable vendoring semantics.
 	GO_EXTLINK_ENABLED
 		Whether the linker should use external linking mode
 		when using -linkmode=auto with code that uses cgo.
@@ -1265,10 +1262,10 @@ unless it is being referred to by that import path. In this way, import comments
 let package authors make sure the custom import path is used and not a
 direct path to the underlying code hosting site.
 
-If the vendoring experiment is enabled (see 'go help gopath'),
-then import path checking is disabled for code found within vendor trees.
-This makes it possible to copy code into alternate locations in vendor trees
-without needing to update import comments.
+If vendoring is enabled (see 'go help gopath'), then import path checking is
+disabled for code found within vendor trees. This makes it possible to copy
+code into alternate locations in vendor trees without needing to update import
+comments.
 
 See https://golang.org/s/go14customimport for details.
 

src/cmd/go/help.go

@@ -269,10 +269,10 @@ unless it is being referred to by that import path. In this way, import comments
 let package authors make sure the custom import path is used and not a
 direct path to the underlying code hosting site.
 
-If the vendoring experiment is enabled (see 'go help gopath'),
-then import path checking is disabled for code found within vendor trees.
-This makes it possible to copy code into alternate locations in vendor trees
-without needing to update import comments.
+If vendoring is enabled (see 'go help gopath'), then import path checking is
+disabled for code found within vendor trees. This makes it possible to copy
+code into alternate locations in vendor trees without needing to update import
+comments.
 
 See https://golang.org/s/go14customimport for details.
 	`,
@@ -427,9 +427,6 @@ As of Go 1.6 they are on by default. To turn them off, set
 GO15VENDOREXPERIMENT=0. In Go 1.7, the environment
 variable will stop having any effect.
 
-The vendoring semantics are an experiment, and they may change
-in future releases. Once settled, they will be on by default.
-
 See https://golang.org/s/go15vendor for details.
 	`,
 }
@@ -501,7 +498,7 @@ Special-purpose environment variables:
 		File names in stack traces are rewritten from GOROOT to
 		GOROOT_FINAL.
 	GO15VENDOREXPERIMENT
-		Set to 1 to enable the Go 1.5 vendoring experiment.
+		Set to 0 to disable vendoring semantics.
 	GO_EXTLINK_ENABLED
 		Whether the linker should use external linking mode
 		when using -linkmode=auto with code that uses cgo.