Add rationale for the MAP_ANONYMOUS vs. MAP_ANON flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7368 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/ExecutionEngine/JIT/JITEmitter.cpp b/lib/ExecutionEngine/JIT/JITEmitter.cpp
index e6dc706..9e62f13 100644
--- a/lib/ExecutionEngine/JIT/JITEmitter.cpp
+++ b/lib/ExecutionEngine/JIT/JITEmitter.cpp
@@ -73,6 +73,7 @@
static const long pageSize = sysconf(_SC_PAGESIZE);
#if defined(i386) || defined(__i386__) || defined(__x86__)
+ /* Linux and *BSD tend to have these flags named differently. */
#if defined(MAP_ANON) && !defined(MAP_ANONYMOUS)
# define MAP_ANONYMOUS MAP_ANON
#endif