RFR: 8257460: Further CompilerOracle cleanup [v3]

[Nils Eliasson]

> I got some additional feedback on 8256508: "Improve CompileCommand flag" from Claes.
> 
> 1. The _type field in TypedMethodMatcher is not used any more. It is derived from the option.
> 
> 2. The verify_type argument is only used from whitebox API and the check should be pushed out to that code. The check is needed because the option is passed from java as a String and we need to verify that the value type matches the option type.
>  
> 3. The type parameter to TypedMethodMatcher::match isn't used.
>  
> 4. Some code only used for asserts was moved into assert

Nils Eliasson has updated the pull request incrementally with one additional commit since the last revision:

  Move check of unknown option to slowpaths

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/1528/files
  - new: https://git.openjdk.java.net/jdk/pull/1528/files/0a08c828..e369eb25

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=1528&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=1528&range=01-02

  Stats: 9 lines in 2 files changed: 3 ins; 5 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1528.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1528/head:pull/1528

PR: https://git.openjdk.java.net/jdk/pull/1528