RFR: 8288478: AArch64: Clean up whitespace in assembler_aarch64.hpp

[Andrew Haley]

This is a very light cleanup of the layout of assembler_aarch64.hpp. I also corrected a few section headers that didn't match the section names in the Arm Architectural Reference Manual.

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Commit messages:
 - 8288478: AArch64: Clean up whitespace in assembler_aarch64.hpp
 - 8288478: AArch64: Clean up whitespace in assembler_aarch64.hpp
 - Merge https://urldefense.com/v3/__https://github.com/openjdk/jdk__;!!ACWV5N9M2RV99hQ!Jqb8SxNN9fuIzRgVVgl3AwGprUcz0Jss1_w7-NG-9wN6sTt8_fd4mY1M_9xfHQNzmyJWINbohqHWmVoBDz_WL1wDEw$  into JDK-8288478
 - 8288478: AArch64: Clean up whitespace in assembler_aarch64.hpp

Changes: https://git.openjdk.org/jdk/pull/9185/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9185&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288478
  Stats: 154 lines in 1 file changed: 9 ins; 4 del; 141 mod
  Patch: https://git.openjdk.org/jdk/pull/9185.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9185/head:pull/9185

PR: https://git.openjdk.org/jdk/pull/9185