[clang] Change std::sort to llvm::sort in response to r327219

r327219 added wrappers to std::sort which randomly shuffle the container before
sorting.  This will help in uncovering non-determinism caused due to undefined
sorting order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of
std::sort.

llvm-svn: 328636
diff --git a/clang/lib/Format/FormatTokenLexer.cpp b/clang/lib/Format/FormatTokenLexer.cpp
index 284a3a2..e06e26f 100644
--- a/clang/lib/Format/FormatTokenLexer.cpp
+++ b/clang/lib/Format/FormatTokenLexer.cpp
@@ -38,7 +38,7 @@
 
   for (const std::string &ForEachMacro : Style.ForEachMacros)
     ForEachMacros.push_back(&IdentTable.get(ForEachMacro));
-  std::sort(ForEachMacros.begin(), ForEachMacros.end());
+  llvm::sort(ForEachMacros.begin(), ForEachMacros.end());
 }
 
 ArrayRef<FormatToken *> FormatTokenLexer::lex() {