$PropertyType lookups on class parameters allows variance abuse to sneak through class method checking

[popham]

Flow version: v0.101.0

Expected behavior

If I $PropertyType lookup a covariant property within a class parameter for a class method's parameter (a contravariant position), then Flow should error.

Actual behavior

Flow accepts the method, leading to inconsistencies.

• Link to Try-Flow or Github repo: https://flow.org/try/#0MYGwhgzhAEDSA8BqAggLmgb0QD3QOwFcBbAIwFMAnaAH2ggBcKBLPAcwF8A+TAKGmkRh0yANx9o4gPSToAMRAB7AO50AFgoIgAJtApkAVmWD1o9VWWgAzBSEVKWrOk1Z4w9AnujlgYAhAtmFgAG2EHQCnjQQchhTDDACgBuYMxgePTiRAAUAA7oACQAChQKOZT0AJ4AKhVl8MgANNAARNjNnACU6IkKTDoY7DyDPKCQMAAy0GTY9GR4WjAIWLjQhKSUXLz82XmrxOQUXdA9fZiDwyBkJgDW6Es4+PuUNHSMDpsAvKtkKuNi1wA6bLNSBaSzNDoiaDSaBVVRxXQEdJMIgWEgERyqSB0QjAa6mVQlDGqHiknjSCmUqnUmk08kyOEWay2ZQOaBKBQUa4wHIlMoUEAVaGSem0sXiqmkyplWHQL7LR7rKi0BjMNjsMQjcBQaAADS20B2BWKpXK1VqZHgVSarXaRxO-XOpNGOoAmlMZnMFnqDUa9kr7b1HUMgA