Improve anonType resolution by double checking shape to reduce hash collisions

[grainier]

Description:
$title.

Describe your problem(s)
n/a

Describe your solution(s)
Use double-checks to reduce hash collisions. i.e:

switch(var2.hashCode()) {
        case 105: // 1st check hash
            if (var2.equals("i")) { // 2nd check shape
                return this.i;
            }
            break;
        case 106:
            if (var2.equals("j")) {
                return this.j;
            }
        }

Related Issues (optional):

• issue: Dependencies can become incompatible due to anonymous types #28262
• initial pr: Improve runtime anonymous type resolution #29792