internal/legacy: drop legacy prefix

The legacy prefix made sense when this functionality was part of impl.
Now that it is in its own package called legacy, the legacy prefix is silly.

Change-Id: I9e6ddb6185ce1f701e02768b505e6a05f3986f77
Reviewed-on: https://go-review.googlesource.com/c/152543
Reviewed-by: Herbie Ong <herbie@google.com>
diff --git a/internal/legacy/export.go b/internal/legacy/export.go
index c8059a0..60dbd47 100644
--- a/internal/legacy/export.go
+++ b/internal/legacy/export.go
@@ -18,31 +18,31 @@
 type Export struct{}
 
 func (Export) EnumOf(e interface{}) pvalue.LegacyEnum {
-	return legacyWrapEnum(reflect.ValueOf(e)).ProtoReflect().(pvalue.LegacyEnum)
+	return wrapEnum(reflect.ValueOf(e)).ProtoReflect().(pvalue.LegacyEnum)
 }
 
 func (Export) EnumTypeOf(e interface{}) pref.EnumType {
-	return legacyLoadEnumType(reflect.TypeOf(e))
+	return loadEnumType(reflect.TypeOf(e))
 }
 
 func (Export) MessageOf(m interface{}) pvalue.LegacyMessage {
-	return legacyWrapMessage(reflect.ValueOf(m)).ProtoReflect().(pvalue.LegacyMessage)
+	return wrapMessage(reflect.ValueOf(m)).ProtoReflect().(pvalue.LegacyMessage)
 }
 
 func (Export) MessageTypeOf(m interface{}) pref.MessageType {
-	return legacyLoadMessageType(reflect.TypeOf(m)).Type
+	return loadMessageType(reflect.TypeOf(m)).Type
 }
 
 func (Export) ExtensionTypeOf(d pref.ExtensionDescriptor, t interface{}) pref.ExtensionType {
-	return legacyExtensionTypeOf(d, reflect.TypeOf(t))
+	return extensionTypeOf(d, reflect.TypeOf(t))
 }
 
 func (Export) ExtensionDescFromType(t pref.ExtensionType) *protoV1.ExtensionDesc {
-	return legacyExtensionDescFromType(t)
+	return extensionDescFromType(t)
 }
 
 func (Export) ExtensionTypeFromDesc(d *protoV1.ExtensionDesc) pref.ExtensionType {
-	return legacyExtensionTypeFromDesc(d)
+	return extensionTypeFromDesc(d)
 }
 
 func init() {