Create modules for Frontend IR & its builder from PSI

compiler/fir/psi2fir/build.gradle.kts

@@ -0,0 +1,24 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+plugins {
+    kotlin("jvm")
+    id("jps-compatible")
+}
+
+jvmTarget = "1.6"
+
+dependencies {
+    compile(project(":compiler:psi"))
+    compile(project(":core:descriptors"))
+    compile(project(":compiler:fir:tree"))
+
+    compileOnly(intellijCoreDep()) { includeJars("intellij-core", "annotations") }
+}
+
+sourceSets {
+    "main" { projectDefault() }
+    "test" {}
+}

compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -0,0 +1,9 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.builder
+
+class RawFirBuilder {
+}

compiler/fir/tree/build.gradle.kts

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+plugins {
+    kotlin("jvm")
+    id("jps-compatible")
+}
+
+jvmTarget = "1.6"
+
+dependencies {
+    compile(project(":core:descriptors"))
+    // Necessary only to store bound PsiElement inside FirElement
+    compileOnly(intellijCoreDep()) { includeJars("intellij-core", "annotations") }
+}
+
+sourceSets {
+    "main" { projectDefault() }
+    "test" {}
+}

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirElement.kt

@@ -0,0 +1,8 @@
+/*
+ * Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir
+
+interface FirElement

settings.gradle

@@ -28,6 +28,8 @@ include ":kotlin-build-common",
         ":compiler:resolution",
         ":compiler:serialization",
         ":compiler:psi",
+        ":compiler:fir:tree",
+        ":compiler:fir:psi2fir",
         ":compiler:frontend",
         ":compiler:frontend.java",
         ":compiler:frontend.script",