[3.14] gh-145187: Fix crash on invalid type parameter bound expression in conditional block (GH-145188) (#145196)

gh-145187: Fix crash on invalid type parameter bound expression in conditional block (GH-145188)

Fix parsing crash found by oss-fuzz
(cherry picked from commit 5e61a16c1058e5de66b71dfdc9720d40e9f515d9)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>