[PATCH v3 1/2] MdePkg/BaseLib: Add _fltused to feed MSVC compiler

["Guomin Jiang" <guomin.jiang@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2596

Out of edk2 may need _fltused symbol such as mu_plus
OnScreenKeyboard and UiToolKit. those driver will define the symbol to
feed MSVC, but it will conflict with CryptoPkg. so move the symbol to
BaseLib.

Signed-off-by: Guomin Jiang <guomin.jiang@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
---
 MdePkg/Library/BaseLib/BaseLib.inf |  3 ++-
 MdePkg/Library/BaseLib/FltUsed.c   | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 MdePkg/Library/BaseLib/FltUsed.c

diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index 3586beb0ab..bab31c07c7 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -1,7 +1,7 @@
 ## @file
 #  Base Library implementation.
 #
-#  Copyright (c) 2007 - 2019, Intel Corporation. All rights reserved.<BR>
+#  Copyright (c) 2007 - 2020, Intel Corporation. All rights reserved.<BR>
 #  Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
 #  Portions copyright (c) 2011 - 2013, ARM Ltd. All rights reserved.<BR>
 #
@@ -60,6 +60,7 @@
   String.c
   FilePaths.c
   BaseLibInternals.h
+  FltUsed.c               | MSFT
 
 [Sources.Ia32]
   Ia32/WriteTr.nasm
diff --git a/MdePkg/Library/BaseLib/FltUsed.c b/MdePkg/Library/BaseLib/FltUsed.c
new file mode 100644
index 0000000000..c065594266
--- /dev/null
+++ b/MdePkg/Library/BaseLib/FltUsed.c
@@ -0,0 +1,14 @@
+/** @file
+  Declare _fltused symbol for MSVC
+
+  MSVC need this symbol for float, andd it here to feed MSVC. it may remove
+  if MSVC not need it any more.
+
+  Copyright (c) 2020 - 2020, Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+//
+// Just for MSVC float
+//
+int _fltused = 0x1;
-- 
2.25.1.windows.1