Don't assume we want the iOS ABI if running simarm on Mac and the EABI otherwise.

runtime/BUILD.gn

 # Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 # TODO(zra): These build arguments should likely be moved to a gni file that is
 # included in BUILD.gn files that care about the values of the flags. For now,
 # since the GN build only happens as part of a Mojo build there is no need for
 # the indirection.
 declare_args() {
   # Instead of using is_debug, we introduce a different flag for specifying a
@@ skipping 86 matching lines @@
 config("dart_config") {
   defines = []
 
   if (dart_experimental_interpreter) {
     dart_target_arch = "dbc"
   }
 
   if (dart_target_arch != "") {
     if (dart_target_arch == "arm") {
       defines += [ "TARGET_ARCH_ARM" ]
+      if (target_os == "mac" || target_os == "ios") {
+        defines += [ "TARGET_ABI_IOS" ]
+      } else {
+        defines += [ "TARGET_ABI_EABI" ]
+      }
     } else if (dart_target_arch == "arm64") {
       defines += [ "TARGET_ARCH_ARM64" ]
     } else if (dart_target_arch == "mips") {
       defines += [ "TARGET_ARCH_MIPS" ]
     } else if (dart_target_arch == "x64") {
       defines += [ "TARGET_ARCH_X64" ]
     } else if (dart_target_arch == "ia32") {
       defines += [ "TARGET_ARCH_IA32" ]
     } else if (dart_target_arch == "dbc") {
       defines += [ "TARGET_ARCH_DBC" ]
@@ skipping 101 matching lines @@
     "vm:libdart_lib_nosnapshot",
     "vm:libdart_lib",
     "vm:libdart_vm",
     "vm:libdart_platform",
     "third_party/double-conversion/src:libdouble_conversion",
   ]
   sources = [
     "vm/libdart_dependency_helper.cc",
   ]
 }