Fix benchmark.test_compile_hello and benchmark.test_compile_noop to work again.

[juj]

PR #26306 regressed benchmark.test_compile_hello and benchmark.test_compile_noop from working.

http://clbri.com:8010/api/v2/logs/397274/raw_inline

C:\emsdk\emscripten\main>test\runner benchmark.test_compile_hello
using verbose test runner (verbose output requested)
Running 1 tests
Running Emscripten benchmarks... [ including compilation | Fri Apr 24 00:45:10 2026 | em: commit d0cab3f5e315d1edaf0f76b99e8946fcf8252981 | llvm: C:/emsdk/llvm/git/build_main_vs2022_64/Release/bin ]
[1/1] test_compile_hello (test_benchmark.benchmark.test_compile_hello) ...
ERROR

======================================================================
ERROR: test_compile_hello (test_benchmark.benchmark.test_compile_hello)
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Traceback (most recent call last):
  File "C:\emsdk\emscripten\main\test\test_benchmark.py", line 579, in test_compile_hello
    self.do_toolchain_benchmark(['-c', test_file('hello_world.c')])
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\emsdk\emscripten\main\test\test_benchmark.py", line 568, in do_toolchain_benchmark
    b.bench(args)
    ~~~~~~~^^^^^^
TypeError: Benchmarker.bench() missing 1 required positional argument: 'reps'

----------------------------------------------------------------------
Ran 1 test in 0.169s

FAILED (errors=1)