[google gcc-4_7,gcc-4_8,integration] Add bounds checks to vector<bool>

[Jonathan Wakely]

On 23 May 2013 16:56, Paul Pluzhnikov wrote:
>>
>> This patch adds (relatively) cheap bounds and dangling checks to
>> vector<bool>, similar to the checks I added to vector<T> in r195373,
>> r195356, etc.

I was wondering the other day whether we should put these checks on
trunk and enable them automatically when !defined(__OPTIMIZE__)

Now that we have -Og you could use that to disable the checks without
sacrificing debuggability.