test(parser): pin the trailing comment of a TEXT and GLOBL header

Assisted-by: GLM 5.3 Flash

parser/flags_test.go

@@ -226,3 +226,16 @@ func TestGloblFlagsOperand(t *testing.T) {
 		t.Errorf("failed operand must carry no value")
 	}
 }
+
+// TestTrailingCommentInHeader covers the comment a directive line carries:
+// it is the line's trailing text, the operand split hands the frame over
+// before it, and the header parses exactly as it would without it.
+func TestTrailingCommentInHeader(t *testing.T) {
+	txt := parseTextHeader(t, "TEXT \u00b7f(SB), NOSPLIT, $0 /* d */")
+	if !slices.Equal(txt.Flags, []string{"NOSPLIT"}) {
+		t.Errorf("flags = %v, want [NOSPLIT]", txt.Flags)
+	}
+	if txt.FlagVal != 4 || txt.Frame == nil || !txt.Frame.Imm.HasVal || txt.Frame.Imm.Val != 0 {
+		t.Errorf("val = %d frame = %+v, want 4 and $0", txt.FlagVal, txt.Frame)
+	}
+}