Letting the compiler decide how to optimize the multiply by five
gives it the freedom to make better choices for the best technique
for a given target machine.

For example, GCC on x86_64 produces a little bit better code:

Old-way (3 steps with a data dependency between each step):

    shrq    $5, %r13
    leaq    1(%rbx,%r13), %rax
    leaq    (%rax,%rbx,4), %rbx

New-way (3 steps with no dependency between the first two steps
         which can be run in parallel):

    leaq    (%rbx,%rbx,4), %rax     # i*5
    shrq    $5, %r13                # perturb >>= PERTURB_SHIFT
    leaq    1(%r13,%rax), %rbx      # 1 + perturb + i*5

Issue #17934: Add a clear() method to frame objects, to help clean up expensive details (local variables) and break reference cycles.

  evil assert statements.
* Add an additional assert to the new test_name_attribute test that actually
  confirms that a hash created using each h.name results in a new hash sharing
  the same name.

Patch by Madison May.

Issue 18532: Added tests and documentation to formally specify the .name attribute on hashlib objects.

(Original patch by Mark Dickinson.)

Based on patch by Aaron Oakley

Thanks to Stefan Behnel for the report and proposed solution & test.