workflows: Fix version check for X.0.0 releases

.github/workflows/version-check.py

@@ -10,13 +10,21 @@
 
 tag = repo.git.describe(tags = True, abbrev=0)
 m = re.match('llvmorg-([0-9]+)\.([0-9]+)\.([0-9]+)', tag)
-if not m:
-    print("error: Tag is not valid: ", tag)
-    sys.exit(1)
 
-expected_major = m.group(1)
-expected_minor = m.group(2)
-expected_patch = int(m.group(3)) + 1
+if m:
+    expected_major = m.group(1)
+    expected_minor = m.group(2)
+    expected_patch = int(m.group(3)) + 1
+else:
+    # If the previous tag is llvmorg-X-init, then we should be at version X.0.0.
+    m = re.match('llvmorg-([0-9]+)-init', tag)
+    if not m:
+        print("error: Tag is not valid: ", tag)
+        sys.exit(1)
+    expected_major = m.group(1)
+    expected_minor = 0
+    expected_patch = 0
+
 expected_version = f"{expected_major}.{expected_minor}.{expected_patch}"
 
 m = re.match("[0-9]+\.[0-9]+\.[0-9]+", version)