[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

js/js.translator/testData/wasmBox/number/longBitOperations.kt

@@ -0,0 +1,24 @@
+// EXPECTED_REACHABLE_NODES: 1228
+package foo
+
+fun box(): String {
+
+    assertEquals(65536L, 1L shl 16)
+    assertEquals(1L, 65536L shr 16)
+
+    assertEquals(-1L, -1L shr 48)
+    assertEquals(65535L, -1L ushr 48)
+
+    assertEquals(-1L, 0L.inv())
+
+    assertEquals(0b1000L, 0b1100L and 0b1010L)
+    assertEquals(0b1110L, 0b1100L or 0b1010L)
+    assertEquals(0b0110L, 0b1100L xor 0b1010L)
+
+    assertEquals(0xab88ac0021L, 0xabcdef0123L and 0xefaabcdef1L)
+    assertEquals(0xefefffdff3L, 0xabcdef0123L or 0xefaabcdef1L)
+    assertEquals(0x446753dfd2L, 0xabcdef0123L xor 0xefaabcdef1L)
+    assertEquals(-737894400292, 0xabcdef0123L.inv())
+
+    return "OK"
+}