Do not assert when reading an exponent out of range.

llvm-svn: 111534
diff --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
index 2e78557..b87ddf9 100644
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -153,6 +153,7 @@
     value += absExponent * 10;
     if (absExponent >= overlargeExponent) {
       absExponent = overlargeExponent;
+      p = end;  /* outwit assert below */
       break;
     }
     absExponent = value;