RFR: 8352020: [CompileFramework] enable compilation for VectorAPI

[Emanuel Peter]

During work on [JDK-8344942](https://bugs.openjdk.org/browse/JDK-8344942) I discovered that it is currently not possible to compile VectorAPI code because it is still in incubator mode and needs flag "--add-modules=jdk.incubator.vector" for "javac".

Also: "javac" can produce warnings, and that leads to issues like this: [JDK-8351998](https://bugs.openjdk.org/browse/JDK-8351998). We should allow such warnings, they are not compile failures.

Example:

javac --add-modules=jdk.incubator.vector Test.java
warning: [incubating] using incubating module(s): jdk.incubator.vector
1 warning


I added an example test as well.

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Commit messages:
 - whitespace
 - JDK-8352020

Changes: https://git.openjdk.org/jdk/pull/24082/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=24082&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8352020
  Stats: 105 lines in 3 files changed: 99 ins; 0 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/24082.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24082/head:pull/24082

PR: https://git.openjdk.org/jdk/pull/24082