Rollup merge of #75320 - estebank:js-for-i-of-x, r=davidtwco

Detect likely `for foo of bar` JS syntax

Fix #75311.

src/test/ui/issues/issue-40782.fixed

@@ -3,4 +3,6 @@
 fn main() {
     for _i in 0..2 { //~ ERROR missing `in`
     }
+    for _i in 0..2 { //~ ERROR missing `in`
+    }
 }

src/test/ui/issues/issue-40782.rs

@@ -3,4 +3,6 @@
 fn main() {
     for _i 0..2 { //~ ERROR missing `in`
     }
+    for _i of 0..2 { //~ ERROR missing `in`
+    }
 }

src/test/ui/issues/issue-40782.stderr

@@ -4,5 +4,11 @@ error: missing `in` in `for` loop
 LL |     for _i 0..2 {
    |           ^ help: try adding `in` here
 
-error: aborting due to previous error
+error: missing `in` in `for` loop
+  --> $DIR/issue-40782.rs:6:12
+   |
+LL |     for _i of 0..2 {
+   |            ^^ help: try using `in` here instead
+
+error: aborting due to 2 previous errors