Kaleidoscope: Prune __attribute__((used)). Some compilers wouldn't accept one.

llvm-svn: 246268
diff --git a/llvm/examples/Kaleidoscope/Chapter8/toy.cpp b/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
index 5f97a15..b78d901 100644
--- a/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
+++ b/llvm/examples/Kaleidoscope/Chapter8/toy.cpp
@@ -1383,13 +1383,13 @@
 //===----------------------------------------------------------------------===//
 
 /// putchard - putchar that takes a double and returns 0.
-__attribute__((used)) extern "C" double putchard(double X) {
+extern "C" double putchard(double X) {
   fputc((char)X, stderr);
   return 0;
 }
 
 /// printd - printf that takes a double prints it as "%f\n", returning 0.
-__attribute__((used)) extern "C" double printd(double X) {
+extern "C" double printd(double X) {
   fprintf(stderr, "%f\n", X);
   return 0;
 }