RFR: JDK-8256950: Add record attribute support to symbol generator CreateSymbols

[Jan Lahoda]

Adding support for record classes in the historical data for ct.sym. This includes a few changes not strictly needed for the change:
-updating and moving tests into test/langtools, so that it is easier to run them.
-fixing Record attribute reading in javac's ClassReader (used for tests, but seems like the proper thing to do anyway).
-fixing the -Xprint annotation processor to print record component annotations.

Changes to jdk.jdeps' classfile library are needed so that the ct.sym creation works.

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Commit messages:
 - Update CreateSymbolsTest.java
 - Cleaning TODO.
 - Cleaning TODO.
 - Adding test verifying javac can read Record attribute properly.
 - Cleanup.
 - JDK-8256950: Add record attribute support to symbol generator CreateSymbols

Changes: https://git.openjdk.java.net/jdk/pull/1480/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1480&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8256950
  Stats: 1910 lines in 12 files changed: 1147 ins; 745 del; 18 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1480.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1480/head:pull/1480

PR: https://git.openjdk.java.net/jdk/pull/1480