Remove some uses of riscv in tests (#2600)

* Remove some uses of riscv in tests

* Fix typo

* Apply suggestions from code review

* Apply suggestions from code review

Co-authored-by: Benjamin Bouvier <public@benj.me>

cranelift/reader/src/parser.rs

@@ -3678,7 +3678,6 @@ mod tests {
     }
 
     #[test]
-    #[cfg(feature = "riscv")]
     fn isa_spec() {
         assert!(parse_test(
             "target
@@ -3688,7 +3687,7 @@ mod tests {
         .is_err());
 
         assert!(parse_test(
-            "target riscv32
+            "target x86_64
                             set enable_float=false
                             function %foo() system_v {}",
             ParseOptions::default()
@@ -3697,7 +3696,7 @@ mod tests {
 
         match parse_test(
             "set enable_float=false
-                          isa riscv
+                          target x86_64
                           function %foo() system_v {}",
             ParseOptions::default(),
         )
@@ -3707,7 +3706,10 @@ mod tests {
             IsaSpec::None(_) => panic!("Expected some ISA"),
             IsaSpec::Some(v) => {
                 assert_eq!(v.len(), 1);
-                assert_eq!(v[0].name(), "riscv");
+                #[cfg(not(feature = "experimental_x64"))]
+                assert_eq!(v[0].name(), "x86");
+                #[cfg(feature = "experimental_x64")]
+                assert_eq!(v[0].name(), "x64");
             }
         }
     }