[Parse] Add FIXME for bad recovery for incomplete function type

Author: rintaro

test/Parse/errors.swift

@@ -122,6 +122,13 @@ func postRethrows2(_ f: () throws -> Int) -> rethrows Int { // expected-error{{'
   return try f()
 }
 
+func incompleteThrowType() {
+  // FIXME: Bad recovery for incomplete function type.
+  let _: () throws
+  // expected-error @-1 {{consecutive statements on a line must be separated by ';'}}
+  // expected-error @-2 {{expected expression}}
+}
+
 // rdar://21328447
 func fixitThrow0() throw {} // expected-error{{expected throwing specifier; did you mean 'throws'?}} {{20-25=throws}}
 func fixitThrow1() throw -> Int {} // expected-error{{expected throwing specifier; did you mean 'throws'?}} {{20-25=throws}}