Use uint16_t to store register overlaps to reduce static data.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152001 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/CallingConvLower.cpp

@@ -58,7 +58,7 @@ void CCState::HandleByVal(unsigned ValNo, MVT ValVT,
 
 /// MarkAllocated - Mark a register and all of its aliases as allocated.
 void CCState::MarkAllocated(unsigned Reg) {
-  for (const unsigned *Alias = TRI.getOverlaps(Reg);
+  for (const uint16_t *Alias = TRI.getOverlaps(Reg);
        unsigned Reg = *Alias; ++Alias)
     UsedRegs[Reg/32] |= 1 << (Reg&31);
 }