[Test] Save IR bytecode dumps from BytecodeListingHandler to .ir.txt file instead of _ir.txt

This is needed to keep consistency with other dumps and to allow
  test helper plugin to recognize those dumps

compiler/testData/codegen/bytecodeListing/sam/reusedSamWrapperClasses.ir.txt

@@ -0,0 +1,51 @@
+@kotlin.Metadata
+synthetic final class A$sam$java_lang_Runnable$0 {
+    // source: 'reusedSamWrapperClasses.kt'
+    enclosing class A
+    private synthetic final field function: kotlin.jvm.functions.Function0
+    inner (anonymous) class A$sam$java_lang_Runnable$0
+    method <init>(p0: kotlin.jvm.functions.Function0): void
+    public synthetic final method run(): void
+}
+
+@kotlin.Metadata
+final class A$test1$f$1 {
+    // source: 'reusedSamWrapperClasses.kt'
+    enclosing method A.test1()V
+    public final static field INSTANCE: A$test1$f$1
+    inner (anonymous) class A$test1$f$1
+    static method <clinit>(): void
+    method <init>(): void
+    public synthetic bridge method invoke(): java.lang.Object
+    public final method invoke(): void
+}
+
+@kotlin.Metadata
+public final class A {
+    // source: 'reusedSamWrapperClasses.kt'
+    inner (anonymous) class A$sam$java_lang_Runnable$0
+    inner (anonymous) class A$test1$f$1
+    public method <init>(): void
+    public final method test1(): void
+}
+
+@kotlin.Metadata
+final class B$test2$f$1 {
+    // source: 'reusedSamWrapperClasses.kt'
+    enclosing method B.test2()V
+    public final static field INSTANCE: B$test2$f$1
+    inner (anonymous) class B$test2$f$1
+    static method <clinit>(): void
+    method <init>(): void
+    public synthetic bridge method invoke(): java.lang.Object
+    public final method invoke(): void
+}
+
+@kotlin.Metadata
+public final class B {
+    // source: 'reusedSamWrapperClasses.kt'
+    inner (anonymous) class A$sam$java_lang_Runnable$0
+    inner (anonymous) class B$test2$f$1
+    public method <init>(): void
+    public final method test2(): void
+}