renamed keyword arguments not updated everywhere

[nick4f42]

Take this example:

foo(;old) = old

old = 16

foo(;old=old)
foo(;old)

1. Renaming the old in foo(;old) = old to NEW gives

foo(;NEW) = NEW

old = 16

foo(;old=old)  # incorrect
foo(;old)  # incorrect

2. Renaming the old in old = 16 to NEW gives

foo(;old) = old

NEW = 16

foo(;old=NEW)
foo(;NEW)  # incorrect

3. Renaming the first old in foo(;old=old) gives

foo(;old) = old  # incorrect

old = 16

foo(;NEW=old)
foo(;old)  # incorrect

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Additionally, I'm not able to select the first y for renaming the following example:

f(x; y) = y

Putting my cursor over the first y and prompting to rename actually prompts me to rename x. Putting my cursor over the second y works though.