flambda-backend: Fix tests/backtrace/backtrace_bounds_exn (#2001)

Fix the test by applying the existing backtrace normalizing script before
comparing the backtrace to the reference (and update the reference).
See the comment in the sanitize-backtrace.sh script for more info.

testsuite/tests/backtrace/backtrace_bounds_exn.ml

@@ -1,14 +1,8 @@
 (* TEST
-   * setup-ocamlc.byte-build-env
-   ** ocamlc.byte
    flags = "-g"
    ocamlrunparam += ",b=1"
 *)
 
-(* CR mshinwell: re-enable for native once Flambda 2 fixed to say
-   "Raised by primitive operation" in backtraces rather than just
-   "Raised" for bounds check failures *)
-
 (* #11436: bad backtrace for out-of-bounds exception *)
 
 let xs = [| 0; 1; 2 |]

testsuite/tests/backtrace/backtrace_bounds_exn.reference

@@ -1,4 +1,4 @@
 Uncaught exception Invalid_argument("index out of bounds")
-Raised by primitive operation at Backtrace_bounds_exn.bad_bound_fn in file "backtrace_bounds_exn.ml", line 11, characters 7-15
+Raised at Backtrace_bounds_exn.bad_bound_fn in file "backtrace_bounds_exn.ml", line 11, characters 7-15
 Called from Backtrace_bounds_exn in file "backtrace_bounds_exn.ml", line 15, characters 32-54
 OK

testsuite/tests/backtrace/backtrace_bounds_exn.run

@@ -0,0 +1,3 @@
+#!/bin/sh
+(${program} 2>&1 || true) 2>&1 | \
+  ${test_source_directory}/sanitize-backtrace.sh > ${output}