Bug 1357874 - Add more AArch64 support to JS code; r=luke

* Fix a parentheses warning when compiling testGCAllocator.cpp.

* Define GETRANDOM_NR macro for AArch64.

* Disable Android workarounds in jsnativestack.cpp and
  WasmSignalHandlers.cpp for AArch64, because AArch64 is only supported
  on API 21+, in which case those workarounds don't apply.

* Enable trace logging in TraceLogging.cpp.

js/src/jsapi-tests/testGCAllocator.cpp

@@ -315,7 +315,7 @@ mapMemoryAt(void* desired, size_t length)
 
 #if defined(__ia64__) || defined(__aarch64__) || \
     (defined(__sparc__) && defined(__arch64__) && (defined(__NetBSD__) || defined(__linux__)))
-    MOZ_RELEASE_ASSERT(0xffff800000000000ULL & (uintptr_t(desired) + length - 1) == 0);
+    MOZ_RELEASE_ASSERT((0xffff800000000000ULL & (uintptr_t(desired) + length - 1)) == 0);
 #endif
     void* region = mmap(desired, length, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
     if (region == MAP_FAILED)

js/src/jsmath.cpp

@@ -66,6 +66,8 @@
 #  define GETRANDOM_NR 318
 # elif defined(__i386__)
 #  define GETRANDOM_NR 355
+# elif defined(__aarch64__)
+#  define GETRANDOM_NR 278
 # elif defined(__arm__)
 #  define GETRANDOM_NR 384
 // Added other architectures:

js/src/jsnativestack.cpp

@@ -16,7 +16,7 @@
 #  include <pthread_np.h>
 # endif
 
-# if defined(ANDROID)
+# if defined(ANDROID) && !defined(__aarch64__)
 #  include <sys/types.h>
 #  include <unistd.h>
 # endif
@@ -120,11 +120,11 @@ js::GetNativeStackBaseImpl()
     rc = pthread_stackseg_np(pthread_self(), &ss);
     stackBase = (void*)((size_t) ss.ss_sp - ss.ss_size);
     stackSize = ss.ss_size;
-# elif defined(ANDROID)
+# elif defined(ANDROID) && !defined(__aarch64__)
     if (gettid() == getpid()) {
-        // bionic's pthread_attr_getstack doesn't tell the truth for the main
-        // thread (see bug 846670). So we scan /proc/self/maps to find the
-        // segment which contains the stack.
+        // bionic's pthread_attr_getstack prior to API 21 doesn't tell the truth
+        // for the main thread (see bug 846670). So we scan /proc/self/maps to
+        // find the segment which contains the stack.
         rc = -1;
 
         // Put the string on the stack, otherwise there is the danger that it

js/src/vm/TraceLogging.cpp

@@ -61,7 +61,7 @@ rdtsc(void)
     return result;
 
 }
-#elif defined(__arm__)
+#elif defined(__arm__) || defined(__aarch64__)
 
 #include <sys/time.h>
 

js/src/wasm/WasmSignalHandlers.cpp

@@ -1374,6 +1374,7 @@ ProcessHasSignalHandlers()
     sTriedInstallSignalHandlers = true;
 
 #if defined(ANDROID)
+# if !defined(__aarch64__)
     // Before Android 4.4 (SDK version 19), there is a bug
     //   https://android-review.googlesource.com/#/c/52333
     // in Bionic's pthread_join which causes pthread_join to return early when
@@ -1385,6 +1386,7 @@ ProcessHasSignalHandlers()
         if (atol(version_string) < 19)
             return false;
     }
+# endif
 # if defined(MOZ_LINKER)
     // Signal handling is broken on some android systems.
     if (IsSignalHandlingBroken())