RFR: 8326204: yield statements doesn't allow cast expressions with more than 1 type arguments

[Aggelos Biboudis]

A valid use of `yield` that includes a cast to a generic type with multiple parameters, was misdetected by `blockStatement` in parser. This PR addresses this issue.

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Commit messages:
 - 8326204: yield statements doesn't allow cast expressions with more than 1 type arguments

Changes: https://git.openjdk.org/jdk/pull/18196/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18196&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8326204
  Stats: 62 lines in 2 files changed: 61 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18196.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18196/head:pull/18196

PR: https://git.openjdk.org/jdk/pull/18196