8167000: Refine handling of multiple maximally specific abstract methods
Summary: Bring the compiler in sync with spec changes in JDK-7034913
Reviewed-by: vromero, dlsmith

8129962: Investigate performance improvements in langtools combo tests
Summary: New combo API that runs all combo instances in a shared javac context (whenever possible).
Reviewed-by: jjg, jlahoda, vromero

8076543: Add @modules as needed to the langtools tests
Reviewed-by: jjg, shurailine

8015505: Spurious inference error when return type of generic method requires unchecked conversion to target
Summary: Use check context compatibility during 15.12.2.8 check (only when JDK 8 inference is enabled)
Reviewed-by: jjg

8006694: temporarily workaround combo tests are causing time out in several platforms
Reviewed-by: jjg
Contributed-by: maurizio.cimadamore@oracle.com

8005167: execution time of combo tests in javac should be improved
Reviewed-by: jjg, jjh

7124605: typos in javac comments
Reviewed-by: ksrini

7062745: Regression: difference in overload resolution when two methods are maximally specific
Summary: Fix most specific when two methods are maximally specific and only one has non-raw return type
Reviewed-by: jjg, dlsmith