[AMDGPU] Add VerifyScheduling support.

Summary:
This is cut and pasted from the corresponding GenericScheduler
functions.

Reviewers: arsenm, atrick, tstellar, vpykhtin

Subscribers: MatzeB, kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68264

llvm-svn: 373346
diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index 80526af..ff825c0 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -82,6 +82,10 @@
 DumpCriticalPathLength("misched-dcpl", cl::Hidden,
                        cl::desc("Print critical path length to stdout"));
 
+cl::opt<bool> VerifyScheduling(
+    "verify-misched", cl::Hidden,
+    cl::desc("Verify machine instrs before and after machine scheduling"));
+
 } // end namespace llvm
 
 #ifndef NDEBUG
@@ -122,9 +126,6 @@
                                         cl::desc("Enable memop clustering."),
                                         cl::init(true));
 
-static cl::opt<bool> VerifyScheduling("verify-misched", cl::Hidden,
-  cl::desc("Verify machine instrs before and after machine scheduling"));
-
 // DAG subtrees must have at least this many nodes.
 static const unsigned MinSubtreeSize = 8;