[safestack] Lazy initialization of interceptors
[safestack] Lazy initialization of interceptors

Interceptors initialization may try to allocate memory and to call not
initialized allocator.

It's similar to r326025 for CFI.

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@333329 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt