LLGS: support 32-bit on 64-bit hosts

[compnerd]

Summary

Enable the ARM emulation support on AArch64 which can execute ARM32 code. Similarly, handle MIPS 32 on 64.

[xiaobai]

Unsure about the MIPS one but the ARM/ARM64 one looks right to me.

[compnerd]

Fix inclusion

[compnerd]

SVN r361210

[labath]

BTW, there's no fundamental reason why a 64-bit lldb-server has to use instruction emulation for debugging arm32 binaries. Since all arm64 chips support hardware single stepping, we could just teach the arm32 native register context to issue PTRACE_SINGLESTEP commands when build in 64-bit mode, and increase debugging reliability while decreasing lldb-server size. (The same is probably also true for a 32-bit lldb-server running on a 64-bit kernel, but that's something that we would have to detect at runtime.)

Anyway, just an idea, this patch is fine. I was under the impression that arm64 defines arm, but obviously I was wrong.

tools/lldb-server/SystemInitializerLLGS.cpp

 using HostObjectFile = ObjectFileELF;
 #endif
 
-#if defined(__arm__) || defined(__arm) || defined(_ARM) || defined(_M_ARM)
-#define LLDB_TARGET_ARM
-#include "Plugins/Instruction/ARM/EmulateInstructionARM.h"
+#if defined(__arm64__) || defined(__aarch64__) || defined(_M_ARM64)
+#define LLDB_TARGET_ARM64
 #endif
 
-#if defined(__mips__) || defined(mips) || defined(__mips) ||                   \
-    defined(__MIPS__) || defined(_M_MIPS)
-#define LLDB_TARGET_MIPS
-#include "Plugins/Instruction/MIPS/EmulateInstructionMIPS.h"
+#if defined(__arm__) || defined(__arm) || defined(_ARM) || defined(_M_ARM) ||  \
+    defined(LLDB_TARGET_ARM64)
+#define LLDB_TARGET_ARM
+#include "Plugins/Instruction/ARM/EmulateInstructionARM.h"
 #endif
 
 #if defined(__mips64__) || defined(mips64) || defined(__mips64) ||             \

 #include "Plugins/Instruction/MIPS64/EmulateInstructionMIPS64.h"
 #endif
 
+#if defined(__mips__) || defined(mips) || defined(__mips) ||                   \
+    defined(__MIPS__) || defined(_M_MIPS) || defined(LLDB_TARGET_MIPS64)
+#define LLDB_TARGET_MIPS
+#include "Plugins/Instruction/MIPS/EmulateInstructionMIPS.h"
+#endif
+
 using namespace lldb_private;
 
 llvm::Error SystemInitializerLLGS::Initialize() {

 
   HostObjectFile::Initialize();
 
-#if defined(LLDB_TARGET_ARM)
+#if defined(LLDB_TARGET_ARM) || defined(LLDB_TARGET_ARM64)
   EmulateInstructionARM::Initialize();
 #endif
-#if defined(LLDB_TARGET_MIPS)
+#if defined(LLDB_TARGET_MIPS) || defined(LLDB_TARGET_MIPS64)
   EmulateInstructionMIPS::Initialize();
 #endif
 #if defined(LLDB_TARGET_MIPS64)

 void SystemInitializerLLGS::Terminate() {
   HostObjectFile::Terminate();
 
-#if defined(LLDB_TARGET_ARM)
+#if defined(LLDB_TARGET_ARM) || defined(LLDB_TARGET_ARM64)
   EmulateInstructionARM::Terminate();
 #endif
-#if defined(LLDB_TARGET_MIPS)
+#if defined(LLDB_TARGET_MIPS) || defined(LLDB_TARGET_MIPS64)
   EmulateInstructionMIPS::Terminate();
 #endif
 #if defined(LLDB_TARGET_MIPS64)