Format if statements (#4961)

crates/ruff_python_formatter/resources/test/fixtures/ruff/statement/if_statement.py

@@ -0,0 +1,37 @@
+if x == y: # trailing if condition
+    pass # trailing `pass` comment
+    # Root `if` trailing comment
+
+# Leading elif comment
+elif x < y: # trailing elif condition
+    pass
+    # `elif` trailing comment
+
+# Leading else comment
+else: # trailing else condition
+    pass
+    # `else` trailing comment
+
+
+if x == y:
+    if y == z:
+        ...
+
+    if a == b:
+        ...
+    else: # trailing comment
+        ...
+
+    # trailing else comment
+
+# leading else if comment
+elif aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + [
+    11111111111111111111111111,
+    2222222222222222222222,
+    3333333333
+    ]:
+    ...
+
+
+else:
+    ...