IDE: Fix my own lazyness in SynthesizedExtensionAnalyzer::Implementation::isApplicable()

Fixes #76561

Author: slavapestov

lib/IDE/IDETypeChecking.cpp

@@ -369,28 +369,26 @@ struct SynthesizedExtensionAnalyzer::Implementation {
           LookUpConformanceInModule());
 
         SmallVector<Requirement, 2> subReqs;
-        switch (SubstReq.checkRequirement(subReqs)) {
-        case CheckRequirementResult::Success:
-          break;
+        subReqs.push_back(SubstReq);
 
-        case CheckRequirementResult::ConditionalConformance:
-          // FIXME: Need to handle conditional requirements here!
-          break;
+        while (!subReqs.empty()) {
+          auto req = subReqs.pop_back_val();
+          switch (req.checkRequirement(subReqs)) {
+          case CheckRequirementResult::Success:
+          case CheckRequirementResult::PackRequirement:
+          case CheckRequirementResult::ConditionalConformance:
+            break;
 
-        case CheckRequirementResult::PackRequirement:
-          // FIXME
-          assert(false && "Refactor this");
-          return true;
-
-        case CheckRequirementResult::SubstitutionFailure:
-          return true;
-
-        case CheckRequirementResult::RequirementFailure:
-          if (!SubstReq.canBeSatisfied())
+          case CheckRequirementResult::SubstitutionFailure:
             return true;
 
-          MergeInfo.addRequirement(Req);
-          break;
+          case CheckRequirementResult::RequirementFailure:
+            if (!SubstReq.canBeSatisfied())
+              return true;
+
+            MergeInfo.addRequirement(Req);
+            break;
+          }
         }
       }
       return false;