Do not ignore copy operations while finding source instructions

in redundant locals elimination.

Since IgnoringCopySourceInterpreter ignores ALOADs and ASTOREs,
the source instruction of ALOAD K in {ALOAD N, ASTORE K, ALOAD K}
sequence is not ASTORE K. In this case we cannot simply replace K
with N, since there can be multiple {ALOAD N, ASTORE K} sequences
in separate branches. After replacement we get different stack
frames.
This change resolves this.

However, in ReturnUnitMethodTransformer we want to ignore copies
of the same GETSTATIC kotlin/Unit.INSTANCE, since we do not mess
with local variables and just replace ASTORE with ARETURN to help
tail-call optimization.
 #KT-23373: Fixed

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -6514,6 +6514,21 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/coroutines/redundantLocalsElimination")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class RedundantLocalsElimination extends AbstractBlackBoxCodegenTest {
+            public void testAllFilesPresentInRedundantLocalsElimination() throws Exception {
+                KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/coroutines/redundantLocalsElimination"), Pattern.compile("^(.+)\\.kt$"), TargetBackend.JVM, true);
+            }
+
+            @TestMetadata("ktor_receivedMessage.kt")
+            public void testKtor_receivedMessage() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/coroutines/redundantLocalsElimination/ktor_receivedMessage.kt");
+                doTest(fileName);
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/coroutines/stackUnwinding")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)