tests/debuginfo/basic-stepping.rs: Add revisions default-mir-passes, no-SingleUseConsts-mir-pass

To prevent regressions our test must cover the code both inside and
outside of the `SingleUseConsts` MIR pass. Use revisions for that.

Author: Enselic

tests/debuginfo/basic-stepping.rs

@@ -10,19 +10,23 @@
 // Debugger tests need debuginfo
 //@ compile-flags: -g
 
+// FIXME(#128945): SingleUseConsts shouldn't need to be disabled.
+//@ revisions: default-mir-passes no-SingleUseConsts-mir-pass
+//@ [no-SingleUseConsts-mir-pass] compile-flags: -Zmir-enable-passes=-SingleUseConsts
+
 //@ gdb-command: run
 // FIXME(#97083): Should we be able to break on initialization of zero-sized types?
 // FIXME(#97083): Right now the first breakable line is:
 //@ gdb-check:   let mut c = 27;
 //@ gdb-command: next
 //@ gdb-check:   let d = c = 99;
 //@ gdb-command: next
-// FIXME(#33013): gdb-check:   let e = "hi bob";
-// FIXME(#33013): gdb-command: next
-// FIXME(#33013): gdb-check:   let f = b"hi bob";
-// FIXME(#33013): gdb-command: next
-// FIXME(#33013): gdb-check:   let g = b'9';
-// FIXME(#33013): gdb-command: next
+//@ [no-SingleUseConsts-mir-pass] gdb-check:   let e = "hi bob";
+//@ [no-SingleUseConsts-mir-pass] gdb-command: next
+//@ [no-SingleUseConsts-mir-pass] gdb-check:   let f = b"hi bob";
+//@ [no-SingleUseConsts-mir-pass] gdb-command: next
+//@ [no-SingleUseConsts-mir-pass] gdb-check:   let g = b'9';
+//@ [no-SingleUseConsts-mir-pass] gdb-command: next
 //@ gdb-check:   let h = ["whatever"; 8];
 //@ gdb-command: next
 //@ gdb-check:   let i = [1,2,3,4];