Merge pull request #85491 from aidan-hall/disable-pack-specialization

SILOptimizer: Disable PackSpecialization pass until it has been properly fixed.

rdar://164515160

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -527,7 +527,7 @@ void addFunctionPasses(SILPassPipelinePlan &P,
   // of embedded Swift.
   if (!P.getOptions().EmbeddedSwift) {
     P.addGenericSpecializer();
-    P.addPackSpecialization();
+    // P.addPackSpecialization();
     // Run devirtualizer after the specializer, because many
     // class_method/witness_method instructions may use concrete types now.
     P.addDevirtualizer();

test/SILOptimizer/pack_specialization.swift

@@ -1,3 +1,4 @@
+// XFAIL: *
 // RUN: %target-swift-frontend %s -emit-ir -O | %FileCheck %s
 
 // REQUIRES: swift_in_compiler