Unwind: avoid warning about unused typedef

Move the definition of Elf_Addr typedef to the only place it is used, to avoid:

```
llvm-project/libunwind/src/AddressSpace.hpp:501:28: warning: unused typedef 'Elf_Addr' [-Wunused-local-typedef]
```

when compiling for Android with _LIBUNWIND_ARM_EHABI defined and
_LIBUNWIND_SUPPORT_DWARF_UNWIND not defined.

Patch by Joel Klinghed!

llvm-svn: 372427

libunwind/src/AddressSpace.hpp

@@ -497,16 +497,16 @@ inline bool LocalAddressSpace::findUnwindSections(pint_t targetAddr,
 #if !defined(Elf_Phdr)
         typedef ElfW(Phdr) Elf_Phdr;
 #endif
-#if !defined(Elf_Addr) && defined(__ANDROID__)
-        typedef ElfW(Addr) Elf_Addr;
-#endif
 
  #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)
   #if !defined(_LIBUNWIND_SUPPORT_DWARF_INDEX)
    #error "_LIBUNWIND_SUPPORT_DWARF_UNWIND requires _LIBUNWIND_SUPPORT_DWARF_INDEX on this platform."
   #endif
         size_t object_length;
 #if defined(__ANDROID__)
+#if !defined(Elf_Addr)
+        typedef ElfW(Addr) Elf_Addr;
+#endif
         Elf_Addr image_base =
             pinfo->dlpi_phnum
                 ? reinterpret_cast<Elf_Addr>(pinfo->dlpi_phdr) -