Eliminate sign-comparison warnings in APInt

llvm-svn: 140158
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp
index d7291a1..931c885 100644
--- a/llvm/lib/Support/APInt.cpp
+++ b/llvm/lib/Support/APInt.cpp
@@ -54,12 +54,14 @@
       return r;
 
     r = cdigit - 'A';
-    if (r <= radix - 11U)
+    if (r <= unsigned(radix - 11U))
       return r + 10;
 
     r = cdigit - 'a';
-    if (r <= radix - 11U)
+    if (r <= unsigned(radix - 11U))
       return r + 10;
+    
+    radix = 10;
   }
 
   r = cdigit - '0';