[Wasm] Basic CLI

-Xwasm option that will produce wasm instead of JS when used with -Xir-produce-js
Does not affect klib production

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/arguments/K2JSCompilerArguments.kt

@@ -178,6 +178,9 @@ class K2JSCompilerArguments : CommonCompilerArguments() {
     @Argument(value = "-Xerror-tolerance-policy", description = "Set up error tolerance policy (NONE, SEMANTIC, SYNTAX, ALL)")
     var errorTolerancePolicy: String? by NullableStringFreezableVar(null)
 
+    @Argument(value = "-Xwasm", description = "Use experimental WebAssembly compiler backend")
+    var wasm: Boolean by FreezableVar(false)
+
     override fun checkIrSupport(languageVersionSettings: LanguageVersionSettings, collector: MessageCollector) {
         if (!isIrBackendEnabled()) return
 
@@ -196,4 +199,4 @@ fun K2JSCompilerArguments.isPreIrBackendDisabled(): Boolean =
     irOnly || irProduceJs || irProduceKlibFile
 
 fun K2JSCompilerArguments.isIrBackendEnabled(): Boolean =
-    irProduceKlibDir || irProduceJs || irProduceKlibFile
+    irProduceKlibDir || irProduceJs || irProduceKlibFile || wasm

compiler/cli/cli-js/build.gradle.kts

@@ -12,6 +12,7 @@ dependencies {
     compile(project(":compiler:ir.backend.common"))
     compile(project(":compiler:ir.serialization.js"))
     compile(project(":compiler:backend.js"))
+    compile(project(":compiler:backend.wasm"))
     compile(project(":js:js.translator"))
     compile(project(":js:js.serializer"))
     compile(project(":js:js.dce"))

compiler/cli/cli-js/src/org/jetbrains/kotlin/cli/js/K2JsIrCompiler.kt

@@ -8,7 +8,10 @@ package org.jetbrains.kotlin.cli.js
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.util.io.FileUtil
 import com.intellij.openapi.util.text.StringUtil
+import org.jetbrains.kotlin.backend.common.phaser.PhaseConfig
 import org.jetbrains.kotlin.backend.common.serialization.metadata.KlibMetadataVersion
+import org.jetbrains.kotlin.backend.wasm.compileWasm
+import org.jetbrains.kotlin.backend.wasm.wasmPhases
 import org.jetbrains.kotlin.cli.common.*
 import org.jetbrains.kotlin.cli.common.ExitCode.COMPILATION_ERROR
 import org.jetbrains.kotlin.cli.common.ExitCode.OK
@@ -34,6 +37,7 @@ import org.jetbrains.kotlin.ir.backend.js.*
 import org.jetbrains.kotlin.ir.declarations.persistent.PersistentIrFactory
 import org.jetbrains.kotlin.js.config.*
 import org.jetbrains.kotlin.metadata.deserialization.BinaryVersion
+import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.serialization.js.ModuleKind
 import org.jetbrains.kotlin.util.Logger
@@ -216,6 +220,33 @@ class K2JsIrCompiler : CLICompiler<K2JSCompilerArguments>() {
                 MainModule.SourceFiles(sourcesFiles)
             }
 
+            if (arguments.wasm) {
+                val res = compileWasm(
+                    projectJs,
+                    mainModule,
+                    AnalyzerWithCompilerReport(config.configuration),
+                    config.configuration,
+                    PhaseConfig(wasmPhases),
+                    allDependencies = resolvedLibraries,
+                    friendDependencies = friendDependencies,
+                    exportedDeclarations = setOf(FqName("main"))
+                )
+                val outputWasmFile = outputFile.withReplacedExtensionOrNull(outputFile.extension, "wasm")!!
+                outputWasmFile.writeBytes(res.wasm)
+                val outputWatFile = outputFile.withReplacedExtensionOrNull(outputFile.extension, "wat")!!
+                outputWatFile.writeText(res.wat)
+
+                val runner = """
+                    const wasmBinary = read(String.raw`${outputWasmFile.absoluteFile}`, 'binary');
+                    const wasmModule = new WebAssembly.Module(wasmBinary);
+                    const wasmInstance = new WebAssembly.Instance(wasmModule, { runtime, js_code });
+                    wasmInstance.exports.main();
+                """.trimIndent()
+
+                outputFile.writeText(res.js + "\n" + runner)
+                return OK
+            }
+
             val compiledModule = try {
                 compile(
                     projectJs,