[stack protector] Make the StackProtector pass respect ssp-buffer-size.
Previously, SSPBufferSize was assigned the value of the "stack-protector-buffer-size"
attribute after all uses of SSPBufferSize. The effect was that the default
SSPBufferSize was always used during analysis. I moved the check for the
attribute before the analysis; now --param ssp-buffer-size= works correctly again.
Differential Revision: http://reviews.llvm.org/D3349
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@206486
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