RFR: 8308458: Windows build failure with disassembler.cpp(792): warning C4267: '=': conversion from 'size_t' to 'int'

[Jiangli Zhou]

Trivial fix with casting `strlen` return value to `int`.

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Commit messages:
 - 8308458: Windows build failure with disassembler.cpp(792): warning C4267: '=': conversion from 'size_t' to 'int'

Changes: https://git.openjdk.org/jdk/pull/14074/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=14074&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8308458
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/14074.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/14074/head:pull/14074

PR: https://git.openjdk.org/jdk/pull/14074