nir/shader_bisect: Allow passing in a --lo / --hi to continue a run.

Sometimes you fumble an answer, and would like to not restart from the
beginning (or just want to see the behavior of the script late in the run
if you're debugging it).  Pass in the last bad range, and you can keep
going.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38760>

src/compiler/nir/nir_shader_bisect.py

@@ -47,10 +47,8 @@ def was_good():
 
 
 def bisect(args):
-    lo = 0
+    lo = f'{args.lo:064x}'
-    hi = (1 << (8 * 32)) - 1
+    hi = f'{args.hi:064x}'
-    lo = f'{lo:064x}'
-    hi = f'{hi:064x}'
 
     # Do an initial run to sanity check that the user has actually made
     # nir_shader_bisect_select() select some broken behavior.
@@ -95,6 +93,12 @@ if __name__ == '__main__':
     parser = argparse.ArgumentParser()
 
     parser.add_argument('-d', '--debug', action='store_true')
+    parser.add_argument('--lo', type=lambda x: int(x, base=16),
+                        default=0,
+                        help="NIR_SHADER_BISECT_LO from a bad range, to continue a cancelled run")
+    parser.add_argument('--hi', type=lambda x: int(x, base=16),
+                        default=(1 << (8 * 32)) - 1,
+                        help="NIR_SHADER_BISECT_HI from a bad range, to continue a cancelled run")
     parser.add_argument('cmd')
     parser.add_argument('cmd_args', nargs=argparse.REMAINDER)
     args = parser.parse_args()