RFR: 8314592: Add shortcut to SymbolLookup::find [v6]

[Maurizio Cimadamore]

On Thu, 18 Apr 2024 11:32:13 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> While `SymbolLookup` correctly uses an `Optional` return to denote whether a symbol has been found by the lookup or not (which enables composition of symbol lookups), many clients end up just calling `Optional::get`, or `Optional::orElseThrow()` on the result.
>> 
>> This PR proposes to add a convenience method `SymbolLookup::findOrThrow` that will do a lookup and, if no symbol can be found, throws an `IllegalArgumentException` with a relevant exception message.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Change exception type

We need a test for the new method, e.g. to check that the right exception is thrown, and the message is right. The fact that no test needed to be updated when you changed the exception type is a smell.

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Changes requested by mcimadamore (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18474#pullrequestreview-2009500390