rename 'invalidate' bench to something more clear

src/tools/miri/bench-cargo-miri/range-iteration/Cargo.lock

@@ -3,5 +3,5 @@
 version = 3
 
 [[package]]
-name = "invalidate"
+name = "range-iteration"
 version = "0.1.0"

src/tools/miri/bench-cargo-miri/range-iteration/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "invalidate"
+name = "range-iteration"
 version = "0.1.0"
 edition = "2021"
 

src/tools/miri/bench-cargo-miri/range-iteration/src/main.rs

@@ -1,3 +1,4 @@
+//! This generates a lot of work for the AllocId part of the GC.
 fn main() {
     // The end of the range is just chosen to make the benchmark run for a few seconds.
     for _ in 0..50_000 {}