Unfortunately, even for an empty generator, we still use 8 register for various things (try-finally, copies of generator object, parser-introduced temporaries). I will try to get rid of these in separate CLs.
Changes:
- SuspendGenerator bytecode now takes register list to save.
- ResumeGenerator was split into two bytecodes:
* Resume generator reads the state out and marks the generator as
'executing'.
* RestoreGeneratorRegisters reloads the registers from
the generator.
+ this required adding support for output register list.
- Introduced generator_object_ register in the bytecode generator.
* in subsequent CLs, I will make better use of it, the goal is
to get rid if the .generator_object local variable.
- Taught register optimizer to flush unassigned registers.
BUG=v8:6379
Review-Url: https://codereview.chromium.org/2894293003
Cr-Commit-Position: refs/heads/master@{#45675}
