Rename tests and add short test description

Author: VirrageS

src/test/ui/issues/issue-66923.rs src/test/ui/issues/issue-66923-show-error-for-correct-call.rs

@@ -1,3 +1,5 @@
+// This test checks that errors are showed for lines with `collect` rather than `push` method.
+
 fn main() {
     let v = vec![1_f64, 2.2_f64];
     let mut fft: Vec<Vec<f64>> = vec![];

src/test/ui/issues/issue-66923.stderr src/test/ui/issues/issue-66923-show-error-for-correct-call.stderr

@@ -1,13 +1,13 @@
 error[E0277]: a collection of type `std::vec::Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923.rs:6:39
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:8:39
    |
 LL |     let x2: Vec<f64> = x1.into_iter().collect();
    |                                       ^^^^^^^ a collection of type `std::vec::Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`
    |
    = help: the trait `std::iter::FromIterator<&f64>` is not implemented for `std::vec::Vec<f64>`
 
 error[E0277]: a collection of type `std::vec::Vec<f64>` cannot be built from an iterator over elements of type `&f64`
-  --> $DIR/issue-66923.rs:10:29
+  --> $DIR/issue-66923-show-error-for-correct-call.rs:12:29
    |
 LL |     let x3 = x1.into_iter().collect::<Vec<f64>>();
    |                             ^^^^^^^ a collection of type `std::vec::Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`