RFR: 8253970: Build error: address argument to atomic builtin must be a pointer to integer or pointer ('volatile narrowOop *' invalid)

[Jie Fu]

__sync_val_compare_and_swap shouldn't call with narrowOop* for clang after JDK-8247912.
Before passing type T to __sync_val_compare_and_swap, the fix converts T to uint32_t* if sizeof(T) == 4.

Testing:
 - Zero VM build on Linux and MacOS with clang
 - Zero VM build on Linux with gcc

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Commit messages:
 - 8253970 Build error: address argument to atomic builtin must be a pointer to integer or pointer ('volatile narrowOop *' invalid)

Changes: https://git.openjdk.java.net/jdk/pull/496/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=496&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253970
  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/496.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/496/head:pull/496

PR: https://git.openjdk.java.net/jdk/pull/496