[PATCH] edksetup.bat: Simplify the step to use CLANGPDB

["Zhiguang Liu" <zhiguang.liu@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2404

Set the below two environment variables in edksetup.bat:
  set CLANG_HOST_BIN=n
  set CLANG_BIN=C:\Program Files\LLVM\bin\
The CLANG_BIN is only be set if it is not defined.

Cc: Liming Gao <liming.gao@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Zhiguang Liu <zhiguang.liu@intel.com>
---
 edksetup.bat | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/edksetup.bat b/edksetup.bat
index 024f57a4b7..bd057d1241 100755
--- a/edksetup.bat
+++ b/edksetup.bat
@@ -113,6 +113,17 @@ if not defined NASM_PREFIX (
     @if not exist "C:\nasm\nasm.exe" echo   Attempting to build modules that require NASM will fail.
 )
 
+:check_CLANGPDB
+@set CLANG_HOST_BIN=n
+if not defined CLANG_BIN (
+    @echo.
+    @echo !!! WARNING !!! CLANG_BIN environment variable is not set
+    @if exist "C:\Program Files\LLVM\bin\clang.exe" (
+        @set CLANG_BIN=C:\Program Files\LLVM\bin\
+        @echo   Found LLVM, setting the environment variable to C:\Program Files\LLVM\bin\
+    )
+)
+
 :check_cygwin
 if defined CYGWIN_HOME (
   if not exist "%CYGWIN_HOME%" (
-- 
2.16.2.windows.1