Don't crash printing the asm for a ConstantExpr PtrToInt just because the int
is narrower than the pointer. This testcase emits:

  .byte (((17) - 16) & 255)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54517 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter.cpp
index 366b8b3..1ee71bd 100644
--- a/lib/CodeGen/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter.cpp
@@ -821,12 +821,13 @@
 
       // We can emit the pointer value into this slot if the slot is an
       // integer slot greater or equal to the size of the pointer.
-      if (Ty->isInteger() &&
-          TD->getABITypeSize(Ty) >= TD->getABITypeSize(Op->getType()))
+      if (TD->getABITypeSize(Ty) >= TD->getABITypeSize(Op->getType()))
         return EmitConstantValueOnly(Op);
-      
-      assert(0 && "FIXME: Don't yet support this kind of constant cast expr");
+
+      O << "((";
       EmitConstantValueOnly(Op);
+      APInt ptrMask = APInt::getAllOnesValue(TD->getABITypeSizeInBits(Ty));
+      O << ") & " << ptrMask.toStringUnsigned() << ')';
       break;
     }
     case Instruction::Add: