Put global classes into the appropriate namespace.

Most of the cases belong into an anonymous namespace. No
functionality change intended.

llvm-svn: 251515
diff --git a/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp b/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
index e920450..63929b1 100644
--- a/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -95,11 +95,13 @@
   llvm_unreachable("Invalid CPU mode");
 }
 
+namespace {
 struct Region {
   ArrayRef<uint8_t> Bytes;
   uint64_t Base;
   Region(ArrayRef<uint8_t> Bytes, uint64_t Base) : Bytes(Bytes), Base(Base) {}
 };
+} // end anonymous namespace
 
 /// A callback function that wraps the readByte method from Region.
 ///