Update debuginfo test for newer lldb

For reasons I don't understand, lldb in Xcode 15 no longer prints objects as:

(long) $0 = 19

instead, it is printing them as:

(long) 19

tests/debuginfo/constant-ordering-prologue.rs

@@ -20,11 +20,11 @@
 // lldb-command:run
 
 // lldb-command:print a
-// lldb-check: = 19
+// lldb-check: 19
 // lldb-command:print b
-// lldb-check: = 20
+// lldb-check: 20
 // lldb-command:print c
-// lldb-check: = 21.5
+// lldb-check: 21.5
 
 fn binding(a: i64, b: u64, c: f64) {
     let x = 0;