Summary: Introduce alignment-safe Copy::conjoint_swap and JVM_CopySwapMemory
Reviewed-by: mikael, dholmes

Reviewed-by: prr

Reviewed-by: erikj

Summary: Correction of failed backport of JDK-8211394 via JDK-8212696.
Reviewed-by: dholmes, coffeys

Reviewed-by: neliasso, kvn

Reviewed-by: kvn

Reviewed-by: dholmes, jcbeyler

Reviewed-by: dbuck

Summary: Backport from JDK12
Reviewed-by: dholmes

Summary: Backport from JDK9
Reviewed-by: dholmes, coffeys

8172850: Anti-dependency on membar causes crash in register allocator due to invalid instruction scheduling
Summary: Regression test and additional asserts. The problem is fixed by 8087341.
Reviewed-by: kvn

Reviewed-by: kvn

Summary: Replace shell script with Java-only code
Reviewed-by: kvn, iignatyev