Fix criterion-cycles-per-byte compilation error on non-x86_64 platforms.

native/libcst/Cargo.toml

@@ -41,9 +41,11 @@ libcst_derive = { path = "../libcst_derive" }
 
 [dev-dependencies]
 criterion = { version = "0.4.0", features = ["html_reports"] }
-criterion-cycles-per-byte = "0.1"
 difference = "2.0.0"
 
+[target.'cfg(target_arch = "x86_64")'.dev-dependencies]
+criterion-cycles-per-byte = "0.1"
+
 [[bench]]
 name = "parser_benchmark"
 harness = false

native/libcst/benches/parser_benchmark.rs

@@ -11,6 +11,7 @@ use std::{
 use criterion::{
     black_box, criterion_group, criterion_main, measurement::Measurement, BatchSize, Criterion,
 };
+#[cfg(target_arch = "x86_64")]
 use criterion_cycles_per_byte::CyclesPerByte;
 use itertools::Itertools;
 use libcst_native::{
@@ -118,9 +119,20 @@ pub fn parse_into_cst_benchmarks<T: Measurement>(c: &mut Criterion<T>) {
     group.finish();
 }
 
+#[cfg(target_arch = "x86_64")]
+fn get_config() -> Criterion {
+    // criterion_cycles_per_byte is only supported on x86
+    Criterion::default().config.with_measurement(CyclesPerByte)
+}
+
+#[cfg(not(target_arch = "x86_64"))]
+fn get_config() -> Criterion {
+    Criterion::default()
+}
+
 criterion_group!(
     name=benches;
-    config = Criterion::default().with_measurement(CyclesPerByte);
+    config=get_config();
     targets=parser_benchmarks, codegen_benchmarks, inflate_benchmarks, tokenize_benchmarks, parse_into_cst_benchmarks
 );
 criterion_main!(benches);