Merge pull request #715 from apple/PR/fix-compiler-builds

add swift syntax to checkouts

Author: shahmishal

common.py

@@ -46,6 +46,7 @@
         'swift-numerics': '1.0.1',
         'swift-system': '1.1.1',
         'swift-experimental-string-processing': 'swift/main',
+        'swift-syntax': 'main',
     },
     'release/5.7': {
         'llvm-project': 'swift/release/5.7',
@@ -259,6 +260,10 @@ def clone_repos():
             '{}/swift-llvm-bindings '.format(
                 branches[swift_branch]['swift-llvm-bindings'], workspace
             ),
+            '{} [email protected]:apple/swift-syntax.git '
+            '{}/swift-syntax '.format(
+                branches[swift_branch]['swift-syntax'], workspace
+            ),
         ]
 
     process0 = subprocess.Popen([