feat(compiler): Add support for targeting WebAssembly.

The working principle is similar as before with x86, but instead of outputting .asm, it outputs .wat. This can be compiled into .wasm by using the wat2wasm assembler.

compiler/wasm_macros.go

@@ -0,0 +1,50 @@
+package compiler
+
+import (
+	"bytes"
+	"encoding/binary"
+)
+
+type WasmMacros struct {
+	data   *bytes.Buffer
+	Labels map[string]int
+}
+
+func NewWasmMacros() *WasmMacros {
+	return &WasmMacros{
+		data:   new(bytes.Buffer),
+		Labels: map[string]int{},
+	}
+}
+
+func (wm *WasmMacros) SetLabel(label string) string {
+	wm.Labels[label] = wm.data.Len()
+	return ""
+}
+
+func (wm *WasmMacros) GetLabel(label string) int {
+	return wm.Labels[label]
+}
+
+func (wm *WasmMacros) DataB(value byte) string {
+	binary.Write(wm.data, binary.LittleEndian, value)
+	return ""
+}
+
+func (wm *WasmMacros) DataW(value uint16) string {
+	binary.Write(wm.data, binary.LittleEndian, value)
+	return ""
+}
+
+func (wm *WasmMacros) DataD(value uint32) string {
+	binary.Write(wm.data, binary.LittleEndian, value)
+	return ""
+}
+
+func (wm *WasmMacros) ToByte(value int) byte {
+	return byte(value)
+}
+
+func (wm *WasmMacros) Data() []byte {
+	return wm.data.Bytes()
+}