[WASM] Initial infrastructure

- New module ":compiler:backend.wasm"
    - Initial compiler infra (driver, phaser, context)
    - Subset of Wasm AST
    - Skeleton of IR -> Wasm AST
    - Wasm AST -> WAT transformer

- Testing infra

- SpiderMonkey jsshell tool

compiler/ir/serialization.js/build.gradle.kts

@@ -189,9 +189,7 @@ val generateReducedRuntimeKLib by eagerTask<NoDebugJavaExec> {
     )
 }
 
-val generateWasmRuntimeKLib by task<NoDebugJavaExec> {
-    dependsOn(reducedRuntimeSources)
-
+val generateWasmRuntimeKLib by eagerTask<NoDebugJavaExec> {
     buildKLib(sources = listOf("$rootDir/libraries/stdlib/wasm"),
               dependencies = emptyList(),
               outPath = "$buildDir/wasmRuntime/klib",