Merge pull request #62535 from mikeash/robustify-generic-params-vector2

[Reflection] Range-check shapeIndex in createBoundGenericTypeReconstructingParent.

Author: mikeash

include/swift/Reflection/TypeRefBuilder.h

@@ -569,6 +569,9 @@ class TypeRefBuilder {
     if (!mangling.isSuccess())
       return nullptr;
 
+    if (shapeIndex >= genericParamsPerLevel.size())
+      return nullptr;
+
     auto numGenericArgs = genericParamsPerLevel[shapeIndex];
 
     auto startOffsetFromEnd = argsIndex + numGenericArgs;