Improved documentation

src/build/asm/Assembler.go

@@ -4,12 +4,12 @@ import "maps"
 
 // Assembler contains a list of instructions.
 type Assembler struct {
-	Instructions []Instruction
 	Data         map[string][]byte
+	Instructions []Instruction
 }
 
 // Merge combines the contents of this assembler with another one.
 func (a *Assembler) Merge(b Assembler) {
-	a.Instructions = append(a.Instructions, b.Instructions...)
 	maps.Copy(a.Data, b.Data)
+	a.Instructions = append(a.Instructions, b.Instructions...)
 }