[NFC] IRGen: Extracted function.

Author: nate-chandler

lib/IRGen/Outlining.cpp

@@ -32,6 +32,25 @@
 using namespace swift;
 using namespace irgen;
 
+static GenericEnvironment *digOutGenericEnvironment(CanType loweredType) {
+  // Find a non-local, non-opaque archetype in the type and pull out
+  // its generic environment.
+  // TODO: we ought to be able to usefully minimize this
+
+  GenericEnvironment *env = nullptr;
+  loweredType.findIf([&env](CanType t) -> bool {
+    if (auto arch = dyn_cast<ArchetypeType>(t)) {
+      if (!isa<PrimaryArchetypeType>(arch) && !isa<PackArchetypeType>(arch))
+        return false;
+      env = arch->getGenericEnvironment();
+      return true;
+    }
+    return false;
+  });
+
+  return env;
+}
+
 OutliningMetadataCollector::OutliningMetadataCollector(
     SILType T, IRGenFunction &IGF, LayoutIsNeeded_t needsLayout,
     DeinitIsNeeded_t needsDeinitTypes)
@@ -141,21 +160,8 @@ irgen::getTypeAndGenericSignatureForManglingOutlineFunction(SILType type) {
   auto loweredType = type.getASTType();
   if (!loweredType->hasArchetype()) return {loweredType, nullptr};
 
-  // Find a non-local, non-opaque archetype in the type and pull out
-  // its generic environment.
-  // TODO: we ought to be able to usefully minimize this
+  GenericEnvironment *env = digOutGenericEnvironment(loweredType);
 
-  GenericEnvironment *env = nullptr;
-  loweredType.findIf([&env](CanType t) -> bool {
-      if (auto arch = dyn_cast<ArchetypeType>(t)) {
-        if (!isa<PrimaryArchetypeType>(arch) &&
-            !isa<PackArchetypeType>(arch))
-          return false;
-        env = arch->getGenericEnvironment();
-        return true;
-      }
-      return false;
-    });
   assert(env && "has archetype but no archetype?!");
   return {loweredType->mapTypeOutOfContext()->getCanonicalType(),
           env->getGenericSignature().getCanonicalSignature()};