Merge pull request #59842 from rjmccall/declare-built-type-earlier

Fix the build on 32-bit targets

Author: nate-chandler

stdlib/public/runtime/MetadataLookup.cpp

@@ -1324,6 +1324,8 @@ class DecodedMetadataBuilder {
   TypeReferenceOwnership ReferenceOwnership;
 
 public:
+  using BuiltType = const Metadata *;
+
   struct BuiltLayoutConstraint {
     bool operator==(BuiltLayoutConstraint rhs) const { return true; }
     operator bool() const { return true; }
@@ -1354,7 +1356,6 @@ class DecodedMetadataBuilder {
       substGenericParameter(substGenericParameter),
       substWitnessTable(substWitnessTable) { }
 
-  using BuiltType = const Metadata *;
   using BuiltTypeDecl = const ContextDescriptor *;
   using BuiltProtocolDecl = ProtocolDescriptorRef;
   using BuiltGenericSignature = const Metadata *;