Initial patch for a64.

src/globals.h

Index: src/globals.h
diff --git a/src/globals.h b/src/globals.h
index 59931bf5ddb3ba7a9908e97b43aaa7915e731791..b36b64cb956cf7a582fdb2190255e8752725fc6b 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -86,6 +86,10 @@ namespace internal {
 #define V8_HOST_ARCH_IA32 1
 #define V8_HOST_ARCH_32_BIT 1
 #define V8_HOST_CAN_READ_UNALIGNED 1
+#elif defined(__AARCH64EL__)
+#define V8_HOST_ARCH_A64 1
+#define V8_HOST_ARCH_64_BIT 1
+#define V8_HOST_CAN_READ_UNALIGNED 1
 #elif defined(__ARMEL__)
 #define V8_HOST_ARCH_ARM 1
 #define V8_HOST_ARCH_32_BIT 1
@@ -99,18 +103,21 @@ namespace internal {
 #define V8_HOST_ARCH_MIPS 1
 #define V8_HOST_ARCH_32_BIT 1
 #else
-#error Host architecture was not detected as supported by v8
+#error "Host architecture was not detected as supported by v8"
 #endif
 
 // Target architecture detection. This may be set externally. If not, detect
 // in the same way as the host architecture, that is, target the native
 // environment as presented by the compiler.
-#if !defined(V8_TARGET_ARCH_X64) && !defined(V8_TARGET_ARCH_IA32) && \
-    !defined(V8_TARGET_ARCH_ARM) && !defined(V8_TARGET_ARCH_MIPS)
+#if !defined(V8_TARGET_ARCH_X64) && !defined(V8_TARGET_ARCH_IA32) &&           \
+    !defined(V8_TARGET_ARCH_A64) && !defined(V8_TARGET_ARCH_ARM) &&            \
+    !defined(V8_TARGET_ARCH_MIPS)
 #if defined(_M_X64) || defined(__x86_64__)
 #define V8_TARGET_ARCH_X64 1
 #elif defined(_M_IX86) || defined(__i386__)
 #define V8_TARGET_ARCH_IA32 1
+#elif defined(__AARCH64EL__)
+#define V8_TARGET_ARCH_A64 1
 #elif defined(__ARMEL__)
 #define V8_TARGET_ARCH_ARM 1
 #elif defined(__MIPSEL__)
@@ -131,6 +138,10 @@ namespace internal {
     !(defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_ARM)))
 #error Target architecture arm is only supported on arm and ia32 host
 #endif
+#if (defined(V8_TARGET_ARCH_A64) && \
+    !(defined(V8_HOST_ARCH_X64) || defined(V8_HOST_ARCH_A64)))
+#error Target architecture a64 is only supported on a64 and x64 host
+#endif
 #if (defined(V8_TARGET_ARCH_MIPS) && \
     !(defined(V8_HOST_ARCH_IA32) || defined(V8_HOST_ARCH_MIPS)))
 #error Target architecture mips is only supported on mips and ia32 host
@@ -140,6 +151,9 @@ namespace internal {
 // Setting USE_SIMULATOR explicitly from the build script will force
 // the use of a simulated environment.
 #if !defined(USE_SIMULATOR)
+#if (defined(V8_TARGET_ARCH_A64) && !defined(V8_HOST_ARCH_A64))
+#define USE_SIMULATOR 1
+#endif
 #if (defined(V8_TARGET_ARCH_ARM) && !defined(V8_HOST_ARCH_ARM))
 #define USE_SIMULATOR 1
 #endif