Prune two MachineInstr.h includes, fix up deps

MachineInstr.h included AliasAnalysis.h, which includes a world of IR
constructs mostly unneeded in CodeGen. Prune it. Same for
DebugInfoMetadata.h.

Noticed with -ftime-trace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375311 91177308-0d34-0410-b5e6-96231b3b80d8
23 files changed