JVM: enable -Xlambdas=class in some codegen tests

Most of these tests check the specific structure of lambdas when they
are generated as classes, and they start to fail once invokedynamic
lambdas are enabled by default.

compiler/testData/codegen/bytecodeText/companion/privateCompanionObjectAccessors_after.kt

@@ -1,4 +1,5 @@
 // !LANGUAGE: +ProperVisibilityForCompanionObjectInstanceField
+// LAMBDAS: CLASS
 
 class Host {
     private companion object {
@@ -8,4 +9,4 @@ class Host {
     fun test() = { foo() }
 }
 
-// 1 synthetic access\$
+// 1 synthetic access\$

compiler/testData/codegen/bytecodeText/companion/protectedCompanionObjectAccessors_after.kt

@@ -1,5 +1,5 @@
 // !LANGUAGE: +ProperVisibilityForCompanionObjectInstanceField
-
+// LAMBDAS: CLASS
 // FILE: Base.kt
 package a
 
@@ -17,4 +17,4 @@ class Host : Base() {
 }
 
 // @Host.class:
-// 1 synthetic access\$
+// 1 synthetic access\$