Inline small functions

[Zoxc]

This adds #[inline] to small functions which should be beneficial to inline.

rustc compilation performance (code size of rustc_driver up by 0.09%):

clap:check                        1.9486s   1.9416s  -0.36%
hashmap-instances:check           0.0629s   0.0626s  -0.52%
helloworld:check                  0.0443s   0.0439s  -0.69%
hyper:check                       0.3011s   0.3000s  -0.36%
regex:check                       1.1505s   1.1468s  -0.33%
syn:check                         1.6989s   1.6904s  -0.50%
syntex_syntax:check               6.8479s   6.8288s  -0.28%
winapi:check                      8.3437s   8.2967s  -0.56%

Total                            20.3979s  20.3108s  -0.43%
Summary                           4.0000s   3.9820s  -0.45%

This is the effect on compile time this has on my HashMap compile time benchmark:

hashmap-instances:check           0.0635s   0.0632s  -0.33%
hashmap-instances:release        32.0928s  32.4440s  +1.09%
hashmap-instances:debug           7.2193s   7.2800s  +0.84%

Total                            39.3756s  39.7873s  +1.05%
Summary                           1.5000s   1.5080s  +0.54%

We saw a 1.6% improvement in rustc's build time for a -20% improvement on hashmap-instances:release on rust-lang/rust#87233. So I would expect around a 0.08% regression for rustc's build time from this PR.

[Amanieu]

This looks reasonable: all of these function should compile down to approximately a single assembly instruction, so not inlining them is almost certainly a bug.

@bors r+

[bors]

📌 Commit b50ecce has been approved by Amanieu

[bors]

⌛ Testing commit b50ecce with merge 47a23ab...

[bors]

☀️ Test successful - checks-actions
Approved by: Amanieu
Pushing 47a23ab to master...