8181449: Fix debug.hpp / globalDefinitions.hpp dependency inversion
Summary: Refactor debug.hpp and reverse include dependency.
Reviewed-by: coleenp, stefank, dcubed

8146009: "pure virtual method called" with using new GC logging mechanism
Reviewed-by: dsamersoff, dholmes, mchernov
Contributed-by: marcus.larsson@oracle.com, michail.chernov@oracle.com

Merge

Merge

8140594: Various minor code improvements (compiler)
Summary: Various minor code improvements (compiler)
Reviewed-by: thartmann, kvn

8153723: Change the default logging output for errors and warnings from stderr to stdout
Reviewed-by: mlarsson, sla

8146948: Enable listing of LogTagSets and add support for LogTagSet descriptions
Reviewed-by: rehn, iklam, kbarrett

8145934: Make ttyLocker equivalent for Unified Logging framework
Reviewed-by: rprotacio, stuefe, jrose

8153845: UL log write method missing essential assert
Reviewed-by: mlarsson, brutisso

8153254: Delegate (v)write from Log to LogTagSet
Reviewed-by: stefank, kbarrett

8152538: UL doesn't inline the LogTagSet::is_level check
Reviewed-by: mlarsson, brutisso

8142952: Unified Logging framework does not allow multiple -Xlog: arguments.
Reviewed-by: brutisso, sla

8046148: JEP 158: Unified JVM Logging
Reviewed-by: coleenp, sla