[libunwind] Fix a few libunwind includes

In UnwindCursor.hpp, include config.h before checking _LIBUNWIND_SUPPORT_SEH_UNWIND.

Include libunwind_ext.h for UNW_STEP_SUCCESS.

Differential Revision: https://reviews.llvm.org/D86766

libunwind/src/CompactUnwinder.hpp

@@ -19,6 +19,7 @@
 #include <mach-o/compact_unwind_encoding.h>
 
 #include "Registers.hpp"
+#include "libunwind_ext.h"
 
 #define EXTRACT_BITS(value, mask)                                              \
   ((value >> __builtin_ctz(mask)) & (((1 << __builtin_popcount(mask))) - 1))

libunwind/src/DwarfInstructions.hpp

@@ -16,10 +16,11 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#include "dwarf2.h"
-#include "Registers.hpp"
 #include "DwarfParser.hpp"
+#include "Registers.hpp"
 #include "config.h"
+#include "dwarf2.h"
+#include "libunwind_ext.h"
 
 
 namespace libunwind {

libunwind/src/UnwindCursor.hpp

@@ -38,6 +38,17 @@
 #define _LIBUNWIND_CHECK_LINUX_SIGRETURN 1
 #endif
 
+#include "AddressSpace.hpp"
+#include "CompactUnwinder.hpp"
+#include "config.h"
+#include "DwarfInstructions.hpp"
+#include "EHHeaderParser.hpp"
+#include "libunwind.h"
+#include "libunwind_ext.h"
+#include "Registers.hpp"
+#include "RWMutex.hpp"
+#include "Unwind-EHABI.h"
+
 #if defined(_LIBUNWIND_SUPPORT_SEH_UNWIND)
 // Provide a definition for the DISPATCHER_CONTEXT struct for old (Win7 and
 // earlier) SDKs.
@@ -75,18 +86,6 @@ extern "C" _Unwind_Reason_Code __libunwind_seh_personality(
 
 #endif
 
-#include "config.h"
-
-#include "AddressSpace.hpp"
-#include "CompactUnwinder.hpp"
-#include "config.h"
-#include "DwarfInstructions.hpp"
-#include "EHHeaderParser.hpp"
-#include "libunwind.h"
-#include "Registers.hpp"
-#include "RWMutex.hpp"
-#include "Unwind-EHABI.h"
-
 namespace libunwind {
 
 #if defined(_LIBUNWIND_SUPPORT_DWARF_UNWIND)