Adds armv5 build and test target.

tools/gyp/configurations.gypi

Index: tools/gyp/configurations.gypi
===================================================================
--- tools/gyp/configurations.gypi	(revision 44804)
+++ tools/gyp/configurations.gypi	(working copy)
@@ -17,6 +17,7 @@
       ['"<(target_arch)"=="ia32"', { 'dart_target_arch': 'IA32', }],
       ['"<(target_arch)"=="x64"', { 'dart_target_arch': 'X64', }],
       ['"<(target_arch)"=="arm"', { 'dart_target_arch': 'ARM', }],
+      ['"<(target_arch)"=="armv5"', { 'dart_target_arch': 'ARMV5', }],
       ['"<(target_arch)"=="arm64"', { 'dart_target_arch': 'ARM64', }],
       ['"<(target_arch)"=="simarm"', { 'dart_target_arch': 'SIMARM', }],
       ['"<(target_arch)"=="simarm64"', { 'dart_target_arch': 'SIMARM64', }],
@@ -68,6 +69,13 @@
         ],
       },
 
+      'Dart_armv5_Base': {
+        'abstract': 1,
+        'defines': [
+          'TARGET_ARCH_ARM',
+        ],
+      },
+
       'Dart_simarm64_Base': {
         'abstract': 1,
         'defines': [
@@ -246,6 +254,42 @@
         ],
       },
 
+      'DebugXARMV5': {
+        'inherit_from': [
+          'Dart_Base', 'Dart_armv5_Base', 'Dart_Debug',
+          'Dart_Linux_Base',
+          'Dart_Linux_xarmv5_Base',
+          'Dart_Linux_Debug',
+        ],
+      },
+
+      'ReleaseXARMV5': {
+        'inherit_from': [
+          'Dart_Base', 'Dart_armv5_Base', 'Dart_Release',
+          'Dart_Linux_Base',
+          'Dart_Linux_xarmv5_Base',
+          'Dart_Linux_Release',
+        ],
+      },
+
+      'DebugARMV5': {
+        'inherit_from': [
+          'Dart_Base', 'Dart_armv5_Base', 'Dart_Debug',
+          'Dart_Linux_Base',
+          'Dart_Linux_armv5_Base',
+          'Dart_Linux_Debug',
+        ],
+      },
+
+      'ReleaseARMV5': {
+        'inherit_from': [
+          'Dart_Base', 'Dart_armv5_Base', 'Dart_Release',
+          'Dart_Linux_Base',
+          'Dart_Linux_armv5_Base',
+          'Dart_Linux_Release',
+        ],
+      },
+
       'DebugXARM64': {
         'inherit_from': [
           'Dart_Base', 'Dart_arm64_Base', 'Dart_Debug',