Fix pretty-printing of lifetime bound

[sanxiyn]

Fix #34527.

[rust-highfive]

r? @nrc

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[pnkfelix]

@sanxiyn Thanks for taking this on!

I would prefer if we factored the code a bit more so that we didn't duplicate the lifetime-bound printing loop; you can see the other loop in the fn print_lifetime_def method; I'd just pull that out into a fn print_lifetime_bounds method.

Can you try doing that instead?

[sanxiyn]

Done.

[pnkfelix]

(now that I look at it, I wonder if the right convention would be to print 'c: 'a+'b instead of 'c: 'a + 'b. But I'm not going to let that question hold up this PR.)

[pnkfelix]

@bors r+

[bors]

📌 Commit 3c29fc5 has been approved by pnkfelix