Skip building unused parts when targeting SJLJ

When SJLJ exceptions are used, those functions aren't used.

This fixes build failures on ARM with SJLJ enabled (e.g. on armv7/iOS)
when built using the CMake project files.

Differential Revision: https://reviews.llvm.org/D38249

llvm-svn: 314197
diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp
index f072d55..e9981f4 100644
--- a/libunwind/src/libunwind.cpp
+++ b/libunwind/src/libunwind.cpp
@@ -24,6 +24,7 @@
 #include <stdlib.h>
 
 
+#if !defined(__USING_SJLJ_EXCEPTIONS__)
 #include "AddressSpace.hpp"
 #include "UnwindCursor.hpp"
 
@@ -341,6 +342,7 @@
   DwarfFDECache<LocalAddressSpace>::removeAllIn((LocalAddressSpace::pint_t)fde);
 }
 #endif // defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
+#endif // !defined(__USING_SJLJ_EXCEPTIONS__)