clang/test/CodeGen/blocks-seq.c: FileCheck-ize.
clang/test/CodeGen/2006-01-13-StackSave.c: Nuke llvm's opt and llvm-dis, and FileCheck-ize.

@llvm.stacksave is emitted regardless of "opt -std-compile-opts". We have optimizers' tests in llvm/test/Transforms.
clang/test/CodeGen: Nuke llvm's opt and llvm-dis, and FileCheck-ize two tests. -O1 is sufficient here.
clang/test: [CMake] check-clang doesn't require llvm-dis any more.