perf(gengo): short-circuit AND/OR with literal LHS

Skip the PushBool/PopLogical/branch wrapper when the LHS of .AND. /
.OR. is a bare .T./.F. literal. `.T. .AND. X` emits X alone;
`.F. .AND. X` emits PushBool(false) with X dropped; symmetric for
OR. Common after constant-folding a sub-expression — pairs with
the earlier dead-IF-branch peephole.

FiveSql2 43/43, Harbour compat 56/56. Verified via /tmp/test_andor.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

compiler/gengo/gengo.go

@@ -1938,8 +1938,19 @@ func (g *Generator) emitExpr(expr ast.Expr) {
 			g.emitLiteral(folded)
 			break
 		}
-		// Short-circuit AND/OR: Harbour evaluates right operand only if needed
+		// Short-circuit AND/OR: Harbour evaluates right operand only if needed.
+		// With a literal LHS we can skip the PushBool/PopLogical roundtrip
+		// entirely — .T. .AND. B folds to B, .F. .AND. B folds to false,
+		// and symmetrically for OR.
 		if e.Op == token.AND {
+			if v, ok := boolLiteralValue(e.Left); ok {
+				if v {
+					g.emitExpr(e.Right)
+				} else {
+					g.writeln("t.PushBool(false)")
+				}
+				break
+			}
 			g.emitExpr(e.Left)
 			g.writeln("if !t.PopLogical() {")
 			g.writeln("t.PushBool(false)")
@@ -1947,6 +1958,14 @@ func (g *Generator) emitExpr(expr ast.Expr) {
 			g.emitExpr(e.Right)
 			g.writeln("}")
 		} else if e.Op == token.OR {
+			if v, ok := boolLiteralValue(e.Left); ok {
+				if v {
+					g.writeln("t.PushBool(true)")
+				} else {
+					g.emitExpr(e.Right)
+				}
+				break
+			}
 			g.emitExpr(e.Left)
 			g.writeln("if t.PopLogical() {")
 			g.writeln("t.PushBool(true)")