Increase metadata version to 1.1, hardcode incompatibility with 1.0

Add a temporary option to suppress incompatibility errors when compiling Kotlin
against current IDEA libraries until they are migrated

.idea/kotlinc.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="KotlinCompilerSettings">
-    <option name="additionalArguments" value="-version -Xallow-kotlin-package" />
+    <option name="additionalArguments" value="-version -Xallow-kotlin-package -Xskip-metadata-version-check" />
   </component>
 </project>

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/K2JVMCompiler.kt

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.compiler.plugin.PluginCliOptionProcessingException
 import org.jetbrains.kotlin.compiler.plugin.cliPluginUsageString
 import org.jetbrains.kotlin.config.*
 import org.jetbrains.kotlin.load.java.JvmAbi
+import org.jetbrains.kotlin.load.kotlin.JvmMetadataVersion
 import org.jetbrains.kotlin.load.kotlin.incremental.components.IncrementalCompilationComponents
 import org.jetbrains.kotlin.script.StandardScriptDefinition
 import org.jetbrains.kotlin.util.PerformanceCounter
@@ -128,6 +129,10 @@ open class K2JVMCompiler : CLICompiler<K2JVMCompilerArguments>() {
             shouldReportPerf = false
         }
 
+        if (arguments.skipMetadataVersionCheck) {
+            JvmMetadataVersion.skipCheck = true
+        }
+
         putAdvancedOptions(configuration, arguments)
 
         messageSeverityCollector.report(CompilerMessageSeverity.LOGGING, "Configuring the compilation environment", CompilerMessageLocation.NO_LOCATION)

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/JvmMetadataVersion.kt

@@ -23,11 +23,16 @@ import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion
  * This version includes the version of the core protobuf messages (descriptors.proto) as well as JVM extensions (jvm_descriptors.proto).
  */
 class JvmMetadataVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
-    override fun isCompatible() = this.isCompatibleTo(INSTANCE)
+    // NOTE: 1.1 is incompatible with 1.0 and hence with any other version except 1.1.*
+    override fun isCompatible() =
+            skipCheck || (this.major == 1 && this.minor == 1)
 
     companion object {
+        // TODO: this is a temporary hack which can be removed once we migrate the IDEA code from 1.0 to 1.1
+        var skipCheck: Boolean = false
+
         @JvmField
-        val INSTANCE = JvmMetadataVersion(1, 0, 2)
+        val INSTANCE = JvmMetadataVersion(1, 1, 0)
 
         @JvmField
         val INVALID_VERSION = JvmMetadataVersion()