RFR: 8282849: Loom: Fix minimal debug non-PCH build failure

[Hao Sun]

As described in JBS-8282849, this build failure was introduced by commit
bd25c94 and commit 4d27102. Adding the missing headers would fix it.

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Commit messages:
 - 8282849: Loom: Fix minimal debug non-PCH build failure

Changes: https://git.openjdk.java.net/loom/pull/99/files
 Webrev: https://webrevs.openjdk.java.net/?repo=loom&pr=99&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282849
  Stats: 6 lines in 2 files changed: 6 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/loom/pull/99.diff
  Fetch: git fetch https://git.openjdk.java.net/loom pull/99/head:pull/99

PR: https://git.openjdk.java.net/loom/pull/99