Auto merge of #13159 - emilio:negative-calc, r=notriddle

style: Don't incorrectly clamp values in calc that might not be only lengths.

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components/servo/Cargo.lock

@@ -2268,6 +2268,7 @@ dependencies = [
 name = "style_traits"
 version = "0.0.1"
 dependencies = [
+ "app_units 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "cssparser 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "heapsize 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",