Add a utility program that looks for assert(), NEVER(), ALWAYS(), and

testcase() macros that have side-effects, and reports errors when they are
found.  Also fix a bug that this utility detected as it was being tested.

FossilOrigin-Name: b0b4624fc5d53bb0cc9fae7dad51984837d946ac

src/main.c

@@ -3566,7 +3566,7 @@ int sqlite3_test_control(int op, ...){
     */
     case SQLITE_TESTCTRL_ASSERT: {
       volatile int x = 0;
-      assert( (x = va_arg(ap,int))!=0 );
+      assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
       rc = x;
       break;
     }