Merge pull request #15415 from huonw/conditional-conformance-as

[CS] Handle conditional requirements in existential conversions of literals

lib/Sema/CSSimplify.cpp

@@ -2628,7 +2628,8 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyConformsToConstraint(
   case ConstraintKind::SelfObjectOfProtocol:
     if (auto conformance =
           TC.containsProtocol(type, protocol, DC,
-                              ConformanceCheckFlags::InExpression)) {
+                              (ConformanceCheckFlags::InExpression|
+                               ConformanceCheckFlags::SkipConditionalRequirements))) {
       return recordConformance(*conformance);
     }
     break;