Disable the use of direct TLS in ThreadLocalDetail under MSVC

Summary: The comment tells the truth: StaticMeta doesn't mix well with MSVC's TLS implementation.

Reviewed By: yfeldblum

Differential Revision: D3671274

fbshipit-source-id: 293eb32699ad5cee59965f24f985ec7099c90136

folly/detail/ThreadLocalDetail.h

@@ -43,7 +43,7 @@
 //
 // XXX: Ideally we would instead determine if emutls is in use at runtime as it
 // is possible to configure glibc on Linux to use emutls regardless.
-#if !FOLLY_MOBILE && !defined(__APPLE__)
+#if !FOLLY_MOBILE && !defined(__APPLE__) && !defined(_MSC_VER)
 #define FOLLY_TLD_USE_FOLLY_TLS 1
 #else
 #undef FOLLY_TLD_USE_FOLLY_TLS