Switch most getReservedRegs() clients to the MRI equivalent.

Using the cached bit vector in MRI avoids comstantly allocating and
recomputing the reserved register bit vector.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165983 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index a69a816..bb93bdc 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -257,9 +257,6 @@
   SmallVector<unsigned, 8> SuperDeads;
   SmallVector<unsigned, 8> SuperDefs;
   SmallVector<unsigned, 8> SuperKills;
-#ifndef NDEBUG
-  BitVector Reserved = TRI->getReservedRegs(*MF);
-#endif
 
   for (MachineFunction::iterator MBBI = MF->begin(), MBBE = MF->end();
        MBBI != MBBE; ++MBBI) {
@@ -283,7 +280,7 @@
         unsigned PhysReg = VRM->getPhys(VirtReg);
         assert(PhysReg != VirtRegMap::NO_PHYS_REG &&
                "Instruction uses unmapped VirtReg");
-        assert(!Reserved.test(PhysReg) && "Reserved register assignment");
+        assert(!MRI->isReserved(PhysReg) && "Reserved register assignment");
 
         // Preserve semantics of sub-register operands.
         if (MO.getSubReg()) {