cmake: Set /source-charset:utf-8 for MSVC. Otherwise compiler will use
system codepage as source character set.

* CMakeLists.txt
  (): Add /source-charset:utf-8 to add_compile_options().


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1937124 13f79535-47bb-0310-9956-ffa450edef68

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0db9f40..6ff050f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -374,6 +374,7 @@
     /we4700
     /we4715
     /we4789
+    /source-charset:utf-8
   )
 
   add_compile_definitions(