RFR: 8324865: windows-x64-slowdebug still does not build after JDK-8324840

[Vladimir Kozlov]

[~jwaters] commented in the PR [#17613](https://github.com/openjdk/jdk/pull/17613) that on windows we have strtok_s instead of strtok_r. We may need to #include "runtime/os.hpp" which defined strtok_r for windows instead of <string.hpp>. 

Including os.hpp will increase compilation time for all files which inclide "stringUtils.hpp".
I suggest to move code from .hpp to .cpp file. It is used only by c2 and inlining of this code is not too important.

Tested tier1 and tier2 builds with precompiled headers off.

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Commit messages:
 - 8324865: windows-x64-slowdebug still does not build after JDK-8324840

Changes: https://git.openjdk.org/jdk/pull/17622/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17622&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324865
  Stats: 27 lines in 2 files changed: 14 ins; 11 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17622.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17622/head:pull/17622

PR: https://git.openjdk.org/jdk/pull/17622