対訳表に従って訳を変更

coercion: 型強制
https://github.com/rust-lang-ja/rust-by-example-ja/blob/master/TranslationTable.md

Author: todays-mitsui

src/scope/lifetime/static_lifetime.md

@@ -88,7 +88,7 @@ fn main() {
         let lifetime_num = 9;
 
         // Coerce `NUM` to lifetime of `lifetime_num`:
-        // `NUM`を`lifetime_num`のライフタイムへと圧縮
+        // `NUM`を`lifetime_num`のライフタイムへと強制
         let coerced_static = coerce_static(&lifetime_num);
 
         println!("coerced_static: {}", coerced_static);