test: cover explicit empty else merge flow

Symptom: the PR regression test used an empty ElseBody without marking that the source contained an explicit ELSE token.

Root cause: the empty-ELSE builder fix depends on IfStmt.HasElse, introduced by the custom error-handler routing branch, to distinguish a missing ELSE from an explicitly empty ELSE.

Fix: stack this branch on the HasElse change and set HasElse in the regression test so it exercises the explicit empty-ELSE path.

Tests: go test ./mdl/executor -run TestIfEmptyElseBodyWithContinuingThenEmitsFalseFlowToMerge -v; make build; make test; make lint-go.

Author: hjothamendix

mdl/executor/cmd_microflows_builder_empty_else_merge_test.go

@@ -29,9 +29,9 @@ func TestIfEmptyElseBodyWithContinuingThenEmitsFalseFlowToMerge(t *testing.T) {
 		ThenBody: []ast.MicroflowStatement{
 			&ast.LogStmt{Level: ast.LogInfo, Message: &ast.LiteralExpr{Kind: ast.LiteralString, Value: "in-then"}},
 		},
-		// ElseBody deliberately empty (0 statements). Len-based hasElseBody is
-		// false in this case, so this narrow test drives the "non-hasElseBody"
-		// path. For the hasElseBody + empty body case, see below.
+		// The source had an explicit ELSE token, but no statements in that
+		// branch. That must still build a false split->merge flow.
+		HasElse: true,
 	})
 
 	var split *microflows.ExclusiveSplit