[CMake] clang depends on intrinsics_gen

cc1_main.cpp has the following include chain:

llvm/LinkAllPasses.h
llvm/Analysis/AliasSetTracker.h
llvm/Analysis/AliasAnalysis.h
llvm/IR/CallSite.h
llvm/IR/Attributes.h
llvm/IR/Attributes.gen

This means clang needs to depend on intrinsics_gen.

llvm-svn: 287407