Avoid spurious recompilations when unrelated constructor with default argument changes

[Friendseeker]

Issue

Constructor sometimes has name <init>$default$number (e.g. <init>$default$1, <init>$default$2) instead of <init>. Hence two unrelated constructors have the same name.

#288 ensured that two unrelated <init> constructor have different names by prepending constructor name with class name, however #288 did not handle <init>$default$.

Fix

Prepend <init>$default$ with the class name.

c.c. #288, #578 (comment)

[Friendseeker]

I am deliberating on whether the PR is actually a good change to have.

This particular case <init>$default$ is rare (unlike <init> which is always a used name), while the extra logic introduced by this PR adds overhead to all Def handling. It also makes API phase slightly more confusing.

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I shall request for review and let reviewer determine if this is actually good to have.

[eed3si9n]

Nice!