[stub builder] generate K2 test output for the testsuite where classfiles are generated by the K2 compiler

The result of k1/k2 should be similar here, the differences should be fixed by KT-60764

analysis/decompiled/decompiler-to-file-stubs/testData/clsFileStubBuilder/Contracts/Contracts.k2.txt

@@ -0,0 +1,18 @@
+PsiJetFileStubImpl[package=test]
+  PACKAGE_DIRECTIVE
+    REFERENCE_EXPRESSION[referencedName=test]
+  IMPORT_LIST
+  FUN[fqName=test.myRequire, hasBlockBody=true, hasBody=true, hasTypeParameterListBeforeFunctionName=false, isExtension=false, isTopLevel=true, mayHaveContract=true, name=myRequire]
+    MODIFIER_LIST[public]
+    VALUE_PARAMETER_LIST
+      VALUE_PARAMETER[fqName=null, hasDefaultValue=false, hasValOrVar=false, isMutable=false, name=x]
+        TYPE_REFERENCE
+          USER_TYPE
+            USER_TYPE
+              REFERENCE_EXPRESSION[referencedName=kotlin]
+            REFERENCE_EXPRESSION[referencedName=Boolean]
+    TYPE_REFERENCE
+      USER_TYPE
+        USER_TYPE
+          REFERENCE_EXPRESSION[referencedName=kotlin]
+        REFERENCE_EXPRESSION[referencedName=Unit]

analysis/decompiled/decompiler-to-file-stubs/testData/clsFileStubBuilder/Contracts/Contracts.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // JVM_FILE_NAME: ContractsKt
 
 package test