Make deref_addrof suggestions stricter
Make deref_addrof suggestions stricter

SUGGESTION matches a substring so 'aref' in the testcases can match
'let b = *aref', 'let b = **aref', 'let b = *&aref' etc, which are
all wrong.

graydon/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,aidancully/rust