test(core): fix `Function#name` shim used in IE11 (#41439)
test(core): fix `Function#name` shim used in IE11 (#41439)

Since IE11 does not support `Function#name`, we use a shim in tests that
parses the stringified function to extract the name. Previously, that
shim would cache the computed name on the function to speed up future
invocations. However, this resulted in incorrect values for functions
that "extended" other functions (such as the code generated by
TypeScript when downleveling ES2015 classes that extended other
classes).

To avoid issues such as #41416 (see also [internal discussion][1]), this
commit removes the caching of names. This is not expected to noticeably
affect performance, since (a) it is only used in tests, (b) it is only
used on browsers that do not natively support `Function#name` (i.e.
IE11) and (c) accessing function names is rare and inexpensive compared
to other operations that happen during testing.

[1]: https://angular-team.slack.com/archives/CB4UC1932/p1617285258058000

PR Close #41439

mgechev/angular,angular/angular,brandonroberts/angular,manekinekko/angular,angular/angular,mgechev/angular,brandonroberts/angular,manekinekko/angular,gkalpak/angular,brandonroberts/angular,brandonroberts/angular,angular-indonesia/angular,ocombe/angular,mgechev/angular,gnomeontherun/angular,angular/angular,gnomeontherun/angular,mgechev/angular,shairez/angular,manekinekko/angular,ocombe/angular,gnomeontherun/angular,manekinekko/angular,ocombe/angular,shairez/angular,gnomeontherun/angular,JiaLiPassion/angular,shairez/angular,gkalpak/angular,angular-indonesia/angular,ocombe/angular,shairez/angular,JiaLiPassion/angular,manekinekko/angular,shairez/angular,manekinekko/angular,ocombe/angular,angular/angular,gkalpak/angular,JiaLiPassion/angular,angular-indonesia/angular,angular-indonesia/angular,brandonroberts/angular,JiaLiPassion/angular,ocombe/angular,gkalpak/angular,brandonroberts/angular,mgechev/angular