[build-script] Fix defaults and unittests.

Author: Davide Italiano

utils/build_swift/driver_arguments.py

@@ -629,11 +629,11 @@ def create_argument_parser():
            help='build the Debug variant of LLDB')
 
     option('--lldb-build-with-xcode', store('lldb_build_with_xcode'),
-           const='0',
+           const='1',
            help='build LLDB using xcodebuild, if possible')
 
     option('--lldb-build-with-cmake', store('lldb_build_with_xcode'),
-           const='1',
+           const='0',
            help='build LLDB using CMake')
 
     option('--debug-cmark', store('cmark_build_variant'),

utils/build_swift/tests/expected_options.py

@@ -152,7 +152,7 @@
     'llbuild_assertions': True,
     'lldb_assertions': True,
     'lldb_build_variant': 'Debug',
-    'lldb_build_with_xcode': '1',
+    'lldb_build_with_xcode': '0',
     'llvm_assertions': True,
     'llvm_build_variant': 'Debug',
     'llvm_max_parallel_lto_link_jobs':