[lworld] RFR: 8367698: [lworld] New lint category for code that would not be allowed in the prologue

[Vicente Romero]

This PR introduces a new Xlint category: `initialization`. When enabled it will indicate if some code in an identity class couldn't be placed in the prologue phase. This applies to field initializers and constructors with no explicit `super` invocation. So for example for code like:


class Test {
    int i = 0;

    Test() {
        this.i = 1;
    }
}


a warning will be issued as if there were a super invocation at the end of the constructor, the compiler would issue an error.

PS. The new lint warning had to be disabled during the build as in other case it wouldn't finish

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

Commit messages:
 - 8367698: [lworld] New lint category for code that would not be allowed in the prologue

Changes: https://git.openjdk.org/valhalla/pull/1595/files
  Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1595&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367698
  Stats: 122 lines in 10 files changed: 113 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/valhalla/pull/1595.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1595/head:pull/1595

PR: https://git.openjdk.org/valhalla/pull/1595