Use singleton instances for SPT (stack pointer tracking) in FrameAnalysis.

Summary:
During frame analysis, the functions do not change, and stack pointer tracking
does not need to be performed more than one time.

The current implementation performs the SPT analysis multiple times per
function during the frame analysis, we ca eliminate such computation redundancy.

On HHVM with -frame-opts=hot, this save around a minute which is 40% of the
frame optimization runtime. (129s to 76s).
fdata should be passed for a reasonable evaluation (we need the call graph).

However, this comes at a memory cost, around 2G to the peak when only -frame-opt=hot only is used but,
When all the usual flags are passed, the effect is to the peak is only 200K (measured from one test).

Update:
When jemalloc is used the base became way better and the following runtime are observed:

[jemalloc]
hhvm  85 -->  72.
clang  27 --> 23.

[malloc]
hhvm 129 -->  76.
clang  34   --> 27.

(cherry picked from FBD15707003)