Integrated: Merge lworld

[Vicente Romero]

Merge branch 'lworld' into lw5_merge_lworld
# Conflicts:
#	src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java
#	src/jdk.compiler/share/classes/com/sun/tools/javac/code/Source.java
#	src/jdk.compiler/share/classes/com/sun/tools/javac/code/Types.java
#	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java
#	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Flow.java
#	src/jdk.compiler/share/classes/com/sun/tools/javac/jvm/Gen.java

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Commit messages:
 - Merge branch 'lworld' into lw5_merge_lworld
 - Merge lworld
 - Merge lworld
 - Merge lworld
 - 8347754: [lw5] fix the order of nullness markers in signatures
 - Merge lworld
 - Merge lworld
 - Merge lworld
 - Merge lworld
 - Merge lworld
 - ... and 59 more: https://git.openjdk.org/valhalla/compare/cfd3a727...e6630be9

The merge commit only contains trivial merges, so no merge-specific webrevs have been generated.

Changes: https://git.openjdk.org/valhalla/pull/1789/files
  Stats: 6804 lines in 101 files changed: 6679 ins; 5 del; 120 mod
  Patch: https://git.openjdk.org/valhalla/pull/1789.diff
  Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1789/head:pull/1789

PR: https://git.openjdk.org/valhalla/pull/1789