RFR: Merge lworld [v2]

[Vicente Romero]

> # Conflicts:
> #	src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java
> #	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
> #	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java

Vicente Romero has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains ten commits:

 - Merge branch 'lworld' into universal-tvars_merge_lworld
   
   # Conflicts:
   #	src/jdk.compiler/share/classes/com/sun/tools/javac/code/Flags.java
   #	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
   #	src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Check.java
 - Primitive value conversion
 - updating tests
 - Merge lworld
 - Merge lworld
 - universal type variables: initial prototype
   
   Reviewed-by: mcimadamore
 - Merge lworld
 - Merge lworld
 - Merge lworld

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

Changes: https://git.openjdk.java.net/valhalla/pull/594/files
 Webrev: https://webrevs.openjdk.java.net/?repo=valhalla&pr=594&range=01
  Stats: 796 lines in 22 files changed: 759 ins; 1 del; 36 mod
  Patch: https://git.openjdk.java.net/valhalla/pull/594.diff
  Fetch: git fetch https://git.openjdk.java.net/valhalla pull/594/head:pull/594

PR: https://git.openjdk.java.net/valhalla/pull/594