[gradle-plugin] Run tools with -Xmx3G by default

samples/gradle.properties

@@ -1,2 +1 @@
-konan.home=../../dist
+konan.home=../../dist
-konan.jvmArgs=-Xmx3G

samples/gtk/build.gradle

@@ -1,6 +1,9 @@
 apply plugin: 'konan'
 
-konan.targets = ['macbook', 'linux']
+konan {
+    targets = ['macbook', 'linux']
+    jvmArgs = ['-Xmx8g']
+}
 
 def includePrefixes = [ '/opt/local/include', '/usr/include', '/usr/local/include' ]
 

tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KonanPlugin.kt

@@ -238,7 +238,7 @@ open class KonanExtension {
     var targets = mutableListOf("host")
     var languageVersion: String? = null
     var apiVersion: String? = null
-    val jvmArgs = mutableListOf<String>()
+    var jvmArgs = mutableListOf<String>()
 }
 
 class KonanPlugin @Inject constructor(private val registry: ToolingModelBuilderRegistry)

tools/kotlin-native-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KonanToolRunner.kt

@@ -53,6 +53,10 @@ internal abstract class KonanCliRunner(val toolName: String, val fullName: Strin
             "-ea",
             "-Dkonan.home=${project.konanHome}",
             "-Djava.library.path=${project.konanHome}/konan/nativelib").apply {
+        if (project.konanExtension.jvmArgs.none { it.startsWith("-Xmx") } &&
+            project.jvmArgs.none { it.startsWith("-Xmx") }) {
+            add("-Xmx3G")
+        }
         addAll(project.konanExtension.jvmArgs)
         addAll(project.jvmArgs)
     }