SILVerifier: relax the check for debug vars with different types

Allow two identical debug variables have different types if the types are or contain local archetypes.
When cloning SIL (e.g. in LoopUnroll) local archetypes are uniqued and therefore distinct in cloned instructions.

Fixes a SIL verification error
#84899
rdar://162660981

Author: eeckstein

lib/SIL/Verifier/SILVerifier.cpp

@@ -1657,7 +1657,11 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
 
       require(lhs == rhs ||
               (lhs.isAddress() && lhs.getObjectType() == rhs) ||
-              (DebugVarTy.isAddress() && lhs == rhs.getObjectType()),
+              (DebugVarTy.isAddress() && lhs == rhs.getObjectType()) ||
+
+              // When cloning SIL (e.g. in LoopUnroll) local archetypes are uniqued
+              // and therefore distinct in cloned instructions.
+              (lhs.hasLocalArchetype() && rhs.hasLocalArchetype()),
               "Two variables with different type but same scope!");
     }
 

test/SIL/verifier-archetype-debugvars.sil

@@ -0,0 +1,27 @@
+// RUN: %target-sil-opt %s
+
+sil_stage canonical
+
+import Builtin
+import Swift
+import SwiftShims
+
+protocol P {}
+
+sil_scope 2 { loc "test.swift":1:6 parent @testit : $@convention(thin) (@in_guaranteed any P) -> () }
+sil_scope 3 { loc "test.swift":2:7 parent 2 }
+
+// Check that the verifier does not complain about two alloc_stacks with the same variable but different existential archetypes.
+
+sil @testit : $@convention(thin) (@in_guaranteed any P) -> () {
+bb0(%0 : $*any P):
+  %1 = open_existential_addr immutable_access %0 to $*@opened("2A0E9166-A9AC-11F0-A5A7-0EA13E3AABAF", any P) Self 
+  %2 = alloc_stack [lexical] $@opened("2A0E9166-A9AC-11F0-A5A7-0EA13E3AABAF", any P) Self, var, name "x", loc "test.swift":2:7, scope 3
+  dealloc_stack %2
+  %4 = open_existential_addr immutable_access %0 to $*@opened("3A0E9166-A9AC-11F0-A5A7-0EA13E3AABAF", any P) Self 
+  %5 = alloc_stack [lexical] $@opened("3A0E9166-A9AC-11F0-A5A7-0EA13E3AABAF", any P) Self, var, name "x", loc "test.swift":2:7, scope 3
+  dealloc_stack %5
+  %r = tuple ()
+  return %r
+}
+