Adjusting the tests to the new StringProtocol

Author: Max Moiseev

test/IDE/complete_at_top_level.swift

@@ -398,7 +398,7 @@ func optStr() -> String? { return nil }
 let x = (optStr() ?? "autoclosure").#^TOP_LEVEL_AUTOCLOSURE_1^#
 // AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      characters[#String.CharacterView#]
 // AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      utf16[#String.UTF16View#]
-// AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      utf8[#String.UTF8View#]
+// AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      unicodeScalars[#String.UnicodeScalarView#]
 
 func resyncParserB12() {}
 

test/IDE/complete_value_expr.swift

@@ -1732,7 +1732,7 @@ func testThrows006() {
 // Just sample some String API to sanity check.
 // AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      characters[#String.CharacterView#]
 // AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      utf16[#String.UTF16View#]
-// AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      utf8[#String.UTF8View#]
+// AUTOCLOSURE_STRING: Decl[InstanceVar]/CurrNominal:      unicodeScalars[#String.UnicodeScalarView#]
 func testWithAutoClosure1(_ x: String?) {
   (x ?? "autoclosure").#^AUTOCLOSURE1^#
 }