Change MCSchedModel to be a struct of statically initialized data.

This removes static initializers from the backends which generate this data, and also makes this struct match the other Tablegen generated structs in behaviour

Reviewed by Andy Trick and Chandler C

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@216919 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/TargetSchedule.h

@@ -41,7 +41,7 @@ class TargetSchedModel {
   unsigned MicroOpFactor; // Multiply to normalize microops to resource units.
   unsigned ResourceLCM;   // Resource units per cycle. Latency normalization factor.
 public:
-  TargetSchedModel(): STI(nullptr), TII(nullptr) {}
+  TargetSchedModel(): SchedModel(MCSchedModel::GetDefaultSchedModel()), STI(nullptr), TII(nullptr) {}
 
   /// \brief Initialize the machine model for instruction scheduling.
   ///