Only build watchOS project for armv7k <rdar://problem/44522408>

Author: shahmishal

project.py

@@ -124,6 +124,8 @@ def get_build_command(self, incremental=False):
                 command += ['-configuration', value]
             else:
                 command += ['%s=%s' % (setting, value)]
+        if self._destination == 'generic/platform=watchOS':
+            command += ['ARCHS=armv7k']
 
         return command
 

project_future.py

@@ -124,6 +124,9 @@ def get_build_command(self, incremental=False):
                       'SWIFT_TREAT_WARNINGS_AS_ERRORS=NO'])
         command += self._added_xcodebuild_flags
 
+        if self._destination == 'generic/platform=watchOS':
+            command += ['ARCHS=armv7k']
+
         return command
 
     def get_test_command(self, incremental=False):