Patch initializing EmptySubstitutor service and fix null references

There's a cycle in service initialization and PsiSubstitutor 'clinit'

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinCoreApplicationEnvironment.java.193

@@ -30,6 +30,7 @@ import com.intellij.openapi.fileTypes.PlainTextFileType;
 import com.intellij.openapi.fileTypes.PlainTextLanguage;
 import com.intellij.openapi.fileTypes.PlainTextParserDefinition;
 import com.intellij.openapi.projectRoots.JavaVersionService;
+import com.intellij.openapi.util.KeyWithDefaultValue;
 import com.intellij.openapi.vfs.VirtualFileSystem;
 import com.intellij.psi.*;
 import com.intellij.psi.augment.PsiAugmentProvider;
@@ -52,6 +53,9 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.kotlin.cli.jvm.modules.CoreJrtFileSystem;
 
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
 /**
  * adapted from com.intellij.core.JavaCoreApplicationEnvironment
  * TODO: initiate removal original from com.intellij.core since it seems that there are no usages left
@@ -109,7 +113,14 @@ public class KotlinCoreApplicationEnvironment extends CoreApplicationEnvironment
 
     myApplication.registerService(PsiPackageImplementationHelper.class, new CorePsiPackageImplementationHelper());
 
-    myApplication.registerService(EmptySubstitutor.class, new EmptySubstitutorImpl());
+    EmptySubstitutorImpl emptySubstitutor = new EmptySubstitutorImpl();
+    myApplication.registerService(EmptySubstitutor.class, emptySubstitutor);
+
+    // Patch null values obtained because of cyclic dependency during initialization
+    updateInterfaceField(PsiSubstitutor.class, "KEY", KeyWithDefaultValue.create("SUBSTITUTOR", emptySubstitutor));
+    updateInterfaceField(PsiSubstitutor.class, "EMPTY", emptySubstitutor);
+    updateInterfaceField(PsiSubstitutor.class, "UNKNOWN", PsiSubstitutor.EMPTY);
+
     myApplication.registerService(JavaDirectoryService.class, createJavaDirectoryService());
     myApplication.registerService(JavaVersionService.class, new JavaVersionService());
 
@@ -147,4 +158,41 @@ public class KotlinCoreApplicationEnvironment extends CoreApplicationEnvironment
   protected VirtualFileSystem createJrtFileSystem() {
     return new CoreJrtFileSystem();
   }
+
+  private static void updateInterfaceField(Class<?> klass, String name, Object value) {
+    try {
+      Field field = klass.getDeclaredField(name);
+
+      boolean wasAccessible = field.isAccessible();
+
+      try {
+        if (!wasAccessible) {
+          field.setAccessible(true);
+        }
+
+        Field modifiersField = Field.class.getDeclaredField("modifiers");
+
+        int modifiers = field.getModifiers();
+
+        try {
+          modifiersField.setAccessible(true);
+          modifiersField.setInt(field, modifiers & ~Modifier.FINAL);
+
+          field.set(null, value);
+        }
+        finally {
+          modifiersField.setInt(field, modifiers);
+          modifiersField.setAccessible(false);
+        }
+      }
+      finally {
+        if (!wasAccessible) {
+          field.setAccessible(false);
+        }
+      }
+    }
+    catch (NoSuchFieldException | IllegalAccessException e) {
+      throw new IllegalStateException(e);
+    }
+  }
 }