Add tests for wp_load and wp_store failures

See merge request iris/iris!634

Rename monoid-related operational typeclass instances to include the suffix '_instance'

See merge request iris/iris!629

This was done using the following sed script:
sed -i -E 's/Instance ([a-zA-Z0-9_]+)( .*: (Op|P?Core|ValidN?|Unit) )/Instance \1_instance\2/' $(find iris/algebra -name "*.v")

only locally make uPred_holds a coercion

See merge request iris/iris!631

add _wand lemmas for big-ops

See merge request iris/iris!630

add big_sepM_filter

See merge request iris/iris!627

Generalize `big_opM_filter'` and `big_opS_filter'` to arbitrary monoids, and make arguments consistent.

Add [iSelect], and various tactics based on it

See merge request iris/iris!625

add big_sepS_elem_of_acc_impl

See merge request iris/iris!570

some big_sepL lemmas

See merge request iris/iris!620