Add per-property has<Prop>/set<Prop>/reset<Prop> functions to
MachineFunctionProperties.

/llvm-project/llvm/lib/CodeGen/VirtRegMap.cpp:225:15:
error: unused variable 'ID' [-Werror,-Wunused-variable]
  static char ID;
              ^
1 error generated.

This fixes an assert after allocation failure.

Rather than collecting failed virtual registers and hacking
on the uses after the fact, directly hack on the uses and rewrite
the registers to the dummy assignment immediately.

Previously we were bypassing LiveRegMatrix and directly assigning
in the VirtRegMap. This resulted in inconsistencies where illegal
overlapping assignments were missing. Rather than try to hack in
some system to manage these in LiveRegMatrix (i.e. hacking around
cases with invalid iterators), avoid this by directly using the
physreg. This should also allow removal of special casing in
virtregrewriter for failed allocations.

The callers of these methods already use MCRegister.

Try to use DiagnosticInfo if every register in the class is reserved
by forcing assignment to a reserved register. Also reduces the number
of redundant errors emitted, particularly with fast.

This is still broken in the case of undef uses. There are additional
complications in greedy and fast, so leave it for a separate fix.

Analyses should be marked as analyses.

Otherwise they are prone to get ignored by the legacy analysis cache mechanism and get scheduled redundantly.