FileCheck: Eliminate DOSish \r from input file.

It can pass two tests below on Win32.
  - Clang :: CodeGenCXX/dyncast.cpp
  - LLVM :: CodeGen/ARM/globals.ll

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119023 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/utils/FileCheck/FileCheck.cpp b/utils/FileCheck/FileCheck.cpp
index c6b2ff7..5e30c22 100644
--- a/utils/FileCheck/FileCheck.cpp
+++ b/utils/FileCheck/FileCheck.cpp
@@ -456,6 +456,11 @@
 
   for (const char *Ptr = MB->getBufferStart(), *End = MB->getBufferEnd();
        Ptr != End; ++Ptr) {
+    // Eliminate trailing dosish \r.
+    if (Ptr <= End - 2 && Ptr[0] == '\r' && Ptr[1] == '\n') {
+      continue;
+    }
+
     // If C is not a horizontal whitespace, skip it.
     if (*Ptr != ' ' && *Ptr != '\t') {
       NewFile.push_back(*Ptr);