Merge branch 'ep/varscope'

Merge branch 'ep/varscope'

Shrink lifetime of variables by moving their definitions to an
inner scope where appropriate.

* ep/varscope:
  builtin/gc.c: reduce scope of variables
  builtin/fetch.c: reduce scope of variable
  builtin/commit.c: reduce scope of variables
  builtin/clean.c: reduce scope of variable
  builtin/blame.c: reduce scope of variables
  builtin/apply.c: reduce scope of variables
  bisect.c: reduce scope of variable