Don't put non-static allocas in the static alloca map

Allocas marked inalloca are never static, but we were trying to put them
into the static alloca map if they were in the entry block.  Also add an
assertion in x86 fastisel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200593 91177308-0d34-0410-b5e6-96231b3b80d8