Cherry-pick r322885 from LLVM.

This fixes a build issue when building with libc++ on Windows.

Bug: chromium:801780
Change-Id: I8fa84cefa272c2f3b096b2aada793192a47cc0e3
Reviewed-on: https://swiftshader-review.googlesource.com/16468
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Peter Collingbourne <pcc@google.com>
diff --git a/third_party/llvm-subzero/lib/Support/NativeFormatting.cpp b/third_party/llvm-subzero/lib/Support/NativeFormatting.cpp
index bb86891..88a07bb 100644
--- a/third_party/llvm-subzero/lib/Support/NativeFormatting.cpp
+++ b/third_party/llvm-subzero/lib/Support/NativeFormatting.cpp
@@ -14,6 +14,8 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Format.h"
 
+#include <float.h>
+
 using namespace llvm;
 
 template<typename T, std::size_t N>