Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID

This is done to avoid odd test failures, like the one fixed in r171243.

llvm-svn: 171246
diff --git a/llvm/test/Transforms/GlobalOpt/memset-null.ll b/llvm/test/Transforms/GlobalOpt/memset-null.ll
index 0153402..53ec755 100644
--- a/llvm/test/Transforms/GlobalOpt/memset-null.ll
+++ b/llvm/test/Transforms/GlobalOpt/memset-null.ll
@@ -1,4 +1,4 @@
-; RUN: opt -globalopt %s -S -o - | FileCheck %s
+; RUN: opt -globalopt -S < %s | FileCheck %s
 ; PR10047
 
 %0 = type { i32, void ()* }