Add normalize-coord helper function that clamps coordinate values to
max-safe-int and min-safe-int bounds when reading segments from PathData
binary buffer. Applies normalization to read-segment, impl-walk,
impl-reduce, and impl-lookup functions to ensure coordinates remain
within safe bounds.
Add corresponding test to verify out-of-bounds coordinates are properly
clamped when reading PathData.
Signed-off-by: Andrey Antukh <niwi@niwi.nz>
e511576f66