Merge cockroachdb#79628

79628: logictest: deflake tests with async statements r=AlexTalks a=AlexTalks

While async statements in logictests were introduced in cockroachdb#79010, in some
cases tests with async statements would fail due to a race condition.
This is fixed by updating the logic such that when an async statement is
issued, the goroutine running that statement is ensured to have started
before execution continues to other lines in the test.

Fixes cockroachdb#79565.

Release note: None

Release Justification: Testing change only.

Co-authored-by: Alex Sarkesian <[email protected]>

pkg/sql/logictest/logic.go

@@ -3336,11 +3336,14 @@ func (t *logicTest) execStatement(stmt logicStatement) (bool, error) {
 		}
 		t.pendingStatements[stmt.statementName] = pending
 
+		startedChan := make(chan struct{})
 		go func() {
+			startedChan <- struct{}{}
 			res, err := t.db.Exec(execSQL)
 			pending.resultChan <- pendingExecResult{execSQL, res, err}
 		}()
 
+		<-startedChan
 		return true, nil
 	}