Remove built-in types that existing only for the Go documentation (#675)

Since these types only exist for documenting Go's standard library there
should be no reason to mark them.

Closes #673

rule/redefines-builtin-id.go

@@ -34,32 +34,27 @@ var builtFunctions = map[string]bool{
 }
 
 var builtInTypes = map[string]bool{
-	"ComplexType": true,
-	"FloatType":   true,
-	"IntegerType": true,
-	"Type":        true,
-	"Type1":       true,
-	"bool":        true,
-	"byte":        true,
-	"complex128":  true,
-	"complex64":   true,
-	"error":       true,
-	"float32":     true,
-	"float64":     true,
-	"int":         true,
-	"int16":       true,
-	"int32":       true,
-	"int64":       true,
-	"int8":        true,
-	"rune":        true,
-	"string":      true,
-	"uint":        true,
-	"uint16":      true,
-	"uint32":      true,
-	"uint64":      true,
-	"uint8":       true,
-	"uintptr":     true,
-	"any":         true,
+	"bool":       true,
+	"byte":       true,
+	"complex128": true,
+	"complex64":  true,
+	"error":      true,
+	"float32":    true,
+	"float64":    true,
+	"int":        true,
+	"int16":      true,
+	"int32":      true,
+	"int64":      true,
+	"int8":       true,
+	"rune":       true,
+	"string":     true,
+	"uint":       true,
+	"uint16":     true,
+	"uint32":     true,
+	"uint64":     true,
+	"uint8":      true,
+	"uintptr":    true,
+	"any":        true,
 }
 
 // RedefinesBuiltinIDRule warns when a builtin identifier is shadowed.

testdata/redefines-builtin-id.go

@@ -9,7 +9,7 @@ func append(i, j int) { // MATCH /redefinition of the built-in function append/
 
 }
 
-type Type int16 // MATCH /redefinition of the built-in type Type/
+type string int16 // MATCH /redefinition of the built-in type string/
 
 func delete(set []int64, i int) (y []int64) { // MATCH /redefinition of the built-in function delete/
 	for j, v := range set {