Fix up narrowing conversions in switch statement.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@150082 91177308-0d34-0410-b5e6-96231b3b80d8

src/locale.cpp

diff --git a/src/locale.cpp b/src/locale.cpp
index 128908f..7f40689 100644
--- a/src/locale.cpp
+++ b/src/locale.cpp
@@ -1409,10 +1409,10 @@
                 case 0:
                     ++frm;
                     break;
-                case -1:
+                case size_t(-1):
                     frm_nxt = frm;
                     return error;
-                case -2:
+                case size_t(-2):
                     frm_nxt = frm;
                     return partial;
                 default:
@@ -1515,8 +1515,8 @@
             ++nbytes;
             ++frm;
             break;
-        case -1:
-        case -2:
+        case size_t(-1):
+        case size_t(-2):
             return nbytes;
         default:
             nbytes += n;