Summary: Use conservative assumptions of required alignment for the various garbage collector components into account when determining the maximum heap size that supports compressed oops. Using this conservative value avoids several circular dependencies in the calculation.
Reviewed-by: stefank, dholmes

8014489: tests/gc/arguments/Test(Serial|CMS|Parallel|G1)HeapSizeFlags jtreg tests invoke wrong class
Summary: Some jtreg tests reference unknown classes in the @run and @build lines. This change fixes them.
Reviewed-by: stefank, ehelin

Summary: The patch for 8006088 misses regression tests after a merge error, this CR provides them.
Reviewed-by: jwilhelm, tamao, jmasa

Reviewed-by: ehelin, jwilhelm, jmasa