Fix bad paste-o in the MSVC atomics.

Patch by Иван Сорокин.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73779 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/System/Atomic.cpp b/lib/System/Atomic.cpp
index 5676ca9..416f981 100644
--- a/lib/System/Atomic.cpp
+++ b/lib/System/Atomic.cpp
@@ -59,7 +59,7 @@
 #elif defined(__GNUC__)
   return __sync_add_and_fetch(ptr, 1);
 #elif defined(_MSC_VER)
-  return InterlockedCompareExchange(ptr, new_value, old_value);
+  return InterlockedIncrement(ptr);
 #else
 #  error No atomic increment implementation for your platform!
 #endif
@@ -72,7 +72,7 @@
 #elif defined(__GNUC__)
   return __sync_sub_and_fetch(ptr, 1);
 #elif defined(_MSC_VER)
-  return InterlockedIncrement(ptr);
+  return InterlockedDecrement(ptr);
 #else
 #  error No atomic decrement implementation for your platform!
 #endif