Clean up some Release build warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147289 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Hexagon/HexagonInstrInfo.cpp b/lib/Target/Hexagon/HexagonInstrInfo.cpp
index 69a50d7..ae42da7 100644
--- a/lib/Target/Hexagon/HexagonInstrInfo.cpp
+++ b/lib/Target/Hexagon/HexagonInstrInfo.cpp
@@ -461,7 +461,7 @@
   } else if (VT == MVT::i64) {
     TRC =  Hexagon::DoubleRegsRegisterClass;
   } else {
-    assert(0 && "Cannot handle this register class");
+    llvm_unreachable("Cannot handle this register class");
   }
 
   unsigned NewReg = RegInfo.createVirtualRegister(TRC);
@@ -553,10 +553,6 @@
 
   case Hexagon::JMPR:
     return false;
-    return true;
-
-  default:
-    return true;
   }
 
   return true;
@@ -793,9 +789,8 @@
   case Hexagon::DEALLOC_RET_V4:
     return !invertPredicate ? Hexagon::DEALLOC_RET_cPt_V4 :
                               Hexagon::DEALLOC_RET_cNotPt_V4;
-  default:
-    assert(false && "Unexpected predicable instruction");
   }
+  llvm_unreachable("Unexpected predicable instruction");
 }
 
 
@@ -1243,8 +1238,8 @@
     return true;
   }
 
-  assert(0 && "No offset range is defined for this opcode. Please define it in \
-               the above switch statement!");
+  llvm_unreachable("No offset range is defined for this opcode. "
+                   "Please define it in the above switch statement!");
 }