Auto merge of #10167 - hi-rustin:rustin-patch-test, r=ehuss
Auto merge of #10167 - hi-rustin:rustin-patch-test, r=ehuss

Use 1.51.0 in old cargos test

Remove TODO.
If the default toolchain is the same as "stable", just skip the `avoids_split_debuginfo_collision` test.

rust-lang/cargo,rust-lang/cargo,nipunn1313/cargo,eminence/cargo,rust-lang/cargo,rustyhorde/cargo,rustyhorde/cargo,eminence/cargo,eminence/cargo,eminence/cargo,nipunn1313/cargo,rust-lang/cargo,rustyhorde/cargo,rustyhorde/cargo,nipunn1313/cargo,nipunn1313/cargo