Minor test case fixes

Author: DougGregor

test/Parse/ConditionalCompilation/switch_case.swift

@@ -209,6 +209,7 @@ func foo(x: E, intVal: Int) {
       fallthrough // expected-error {{'fallthrough' from a case which doesn't bind variable 'val'}}
 #if ENABLE_C
     case let val:
+      _ = val
       break
 #endif
     case 2:

test/Parse/matching_patterns.swift

@@ -333,6 +333,6 @@ case (_?)?: break // expected-warning {{case is already handled by previous patt
 let (responseObject: Int?) = op1
 // expected-error @-1 {{expected ',' separator}} {{25-25=,}}
 // expected-error @-2 {{expected pattern}}
-// expected-error @-3 {{expression type 'Int?' is ambiguous without more context}}
+// expected-error @-3 {{cannot convert value of type 'Int?' to specified type '(responseObject: _)'}}