Modernize old-style static asserts. NFC.

llvm-svn: 219588
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index df9121a..7fb7aba 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2737,7 +2737,7 @@
     case ISD::FP_TO_UINT: {
       integerPart x[2];
       bool ignored;
-      assert(integerPartWidth >= 64);
+      static_assert(integerPartWidth >= 64, "APFloat parts too small!");
       // FIXME need to be more flexible about rounding mode.
       APFloat::opStatus s = V.convertToInteger(x, VT.getSizeInBits(),
                             Opcode==ISD::FP_TO_SINT,