RFR: 8271956: AArch64: C1 build failed after JDK-8270947

[Hao Sun]

C1 build failed on AArch64 with the following error message:

  src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp:4642:30: error:
  invalid use of incomplete type 'class CompileTask'


Including the header would fix this error. Note that this header is
included already under COMPILER2 by "opto/compile.hpp".

-------------

Commit messages:
 - 8271956: AArch64: C1 build failed after JDK-8270947

Changes: https://git.openjdk.java.net/jdk/pull/5045/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5045&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8271956
  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5045.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5045/head:pull/5045

PR: https://git.openjdk.java.net/jdk/pull/5045