6912018: CMS: guarantee(head() != 0,"The head of the list cannot be NULL")
Summary: Block too small to split was not correctly putback to free lists.
Reviewed-by: ysr
^build/
^dist/
/nbproject/private/
^src/share/tools/hsdis/build/
^src/share/tools/IdealGraphVisualizer/[a-zA-Z0-9]*/build/
^src/share/tools/IdealGraphVisualizer/build/
^src/share/tools/IdealGraphVisualizer/dist/