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/compiler_macros.go

@@ -0,0 +1,28 @@
+package compiler
+
+import (
+	"github.com/vsariola/sointu"
+)
+
+type CompilerMacros struct {
+	Clip    bool
+	Library bool
+
+	Sine   int // TODO: how can we elegantly access global constants in template, without wrapping each one by one
+	Trisaw int
+	Pulse  int
+	Gate   int
+	Sample int
+	Compiler
+}
+
+func NewCompilerMacros(c Compiler) *CompilerMacros {
+	return &CompilerMacros{
+		Sine:     sointu.Sine,
+		Trisaw:   sointu.Trisaw,
+		Pulse:    sointu.Pulse,
+		Gate:     sointu.Gate,
+		Sample:   sointu.Sample,
+		Compiler: c,
+	}
+}