ICU-10398 merge of r34471, late breaking failure in 32 bit gcc

X-SVN-Rev: 34472
diff --git a/source/i18n/decimfmt.cpp b/source/i18n/decimfmt.cpp
index 10229d0..4a0da8e 100644
--- a/source/i18n/decimfmt.cpp
+++ b/source/i18n/decimfmt.cpp
@@ -1078,7 +1078,7 @@
     }
 
     if (type == Formattable::kInt64) {
-        double fdv = number.getDouble(status);
+        volatile double fdv = number.getDouble(status);
         // Note: conversion of int64_t -> double rounds with some compilers to
         //       values beyond what can be represented as a 64 bit int. Subsequent
         //       testing or conversion with int64_t produces bad results.