[Tablegen] In TargetSchedule.td: Remove unused argument `pfmCounters` from ProcResourceUnits.

[andreadb]

Summary

I am pretty sure that this is a no functional change.

PFM counters don't need to be passed in input to the definition of ProcResourceUnits.
class PfmIssueCounter (r329675) is used to map resources to PFM counter(s).

I verified that there is no difference in the code auto-generated by the subtarget emitter.

@gchatelet is this okay to commit?

Thanks in advance
-Andrea

[gchatelet]

Yep LGTM. Thanks!

llvm/trunk/include/llvm/Target/TargetSchedule.td

 // reservation station.
 //
 // To model both dispatch/issue groups and in-order execution units,
 // create two types of units, one with BufferSize=0 and one with
 // BufferSize=1.
 //
 // SchedModel ties these units to a processor for any stand-alone defs
 // of this class.
-class ProcResourceUnits<ProcResourceKind kind, int num,
-                        list<string> pfmCounters> {
+class ProcResourceUnits<ProcResourceKind kind, int num> {
   ProcResourceKind Kind = kind;
   int NumUnits = num;
   ProcResourceKind Super = ?;
   int BufferSize = -1;
   SchedMachineModel SchedModel = ?;
 }
 
 // EponymousProcResourceKind helps implement ProcResourceUnits by
 // allowing a ProcResourceUnits definition to reference itself. It
 // should not be referenced anywhere else.
 def EponymousProcResourceKind : ProcResourceKind;
 
 // Subtargets typically define processor resource kind and number of
 // units in one place.
-class ProcResource<int num, list<string> pfmCounters = []> : ProcResourceKind,
-  ProcResourceUnits<EponymousProcResourceKind, num, pfmCounters>;
+class ProcResource<int num> : ProcResourceKind,
+  ProcResourceUnits<EponymousProcResourceKind, num>;
 
 class ProcResGroup<list<ProcResource> resources> : ProcResourceKind {
   list<ProcResource> Resources = resources;
   SchedMachineModel SchedModel = ?;
   int BufferSize = -1;
 }
 
 // A target architecture may define SchedReadWrite types and associate