revert: perf($parse): don't use reflective calls in generated functions

This reverts commit cbdf0c2afb.

The commit causes tests failures on IE8. I'm not quite sure why and I can't
investigate now.

Failed build: https://travis-ci.org/angular/angular.js/jobs/30756773

src/ng/parse.js

@@ -1020,7 +1020,7 @@ function getterFn(path, options, fullExp) {
                       // we simply dereference 's' on any .dot notation
                       ? 's'
                       // but if we are first then we check locals first, and if so read it first
-                      : '((k&&k.hasOwnProperty("' + key + '"))?k:s)') + '.' + key + ';\n' +
+                      : '((k&&k.hasOwnProperty("' + key + '"))?k:s)') + '["' + key + '"]' + ';\n' +
               (options.unwrapPromises
                 ? 'if (s && s.then) {\n' +
                   ' pw("' + fullExp.replace(/(["\r\n])/g, '\\$1') + '");\n' +