std lib: fix various typos in comments

Where the spelling changed from British to
US norm (e.g., optimise -> optimize) it follows
the style in that file.

LGTM=adonovan
R=golang-codereviews, adonovan
CC=golang-codereviews
https://golang.org/cl/96980043

3 files changed, 3 insertions, 3 deletions

diff --git a/src/cmd/api/goapi.go b/src/cmd/api/goapi.go
index a62c874210..4bde794a13 100644
--- a/src/cmd/api/goapi.go
+++ b/src/cmd/api/goapi.go
@@ -817,7 +817,7 @@ func (w *Walker) emitFunc(f *types.Func) {
 func (w *Walker) emitMethod(m *types.Selection) {
 	sig := m.Type().(*types.Signature)
 	recv := sig.Recv().Type()
-	// report exported methods with unexported reveiver base type
+	// report exported methods with unexported receiver base type
 	if true {
 		base := recv
 		if p, _ := recv.(*types.Pointer); p != nil {
diff --git a/src/cmd/go/clean.go b/src/cmd/go/clean.go
index 16687f72f7..30a17b87a0 100644
--- a/src/cmd/go/clean.go
+++ b/src/cmd/go/clean.go
@@ -153,7 +153,7 @@ func clean(p *Package) {
 		elem+".test.exe",
 	)
 
-	// Remove a potental executable for each .go file in the directory that
+	// Remove a potential executable for each .go file in the directory that
 	// is not part of the directory's package.
 	for _, dir := range dirs {
 		name := dir.Name()
diff --git a/src/cmd/go/get.go b/src/cmd/go/get.go
index e61da7e2ad..c4217fe24c 100644
--- a/src/cmd/go/get.go
+++ b/src/cmd/go/get.go
@@ -73,7 +73,7 @@ func runGet(cmd *Command, args []string) {
 	}
 	exitIfErrors()
 
-	// Phase 2. Rescan packages and reevaluate args list.
+	// Phase 2. Rescan packages and re-evaluate args list.
 
 	// Code we downloaded and all code that depends on it
 	// needs to be evicted from the package cache so that