Improve `_xxtestfuzz/README.rst`

[sobolevn]

Bug report

Right now there are several points I would like to see improved in this file:

1. We need to clarify that $test_name should be replaced with an actual test name:

   cpython/Modules/_xxtestfuzz/README.rst

   Lines 26 to 29 in 8223544

   	int $test_name (const char* data, size_t size) {
   	...
   	return 0;
   	}

2. _Py_FUZZ_YES is not actually used in our code, docs:

   cpython/Modules/_xxtestfuzz/README.rst

   Line 34 in 8223544

   #if _Py_FUZZ_YES(fuzz_builtin_float)

   code:

   cpython/Modules/_xxtestfuzz/fuzzer.c

   Line 699 in 7fb32e0

   #if !defined(_Py_FUZZ_ONE) || defined(_Py_FUZZ_fuzz_elementtree_parsewhole)

3. Why is fuzz_builtin_float is used in this example? https://github.com/python/cpython/blob/82235449b85165add62c1b200299456a50a1d097/Modules/_xxtestfuzz/README.rst#L34C9-L34C41 It is better to use $test_name. Or even better $fuzz_test_name to have a common prefix.

Linked PRs

• gh-121023: Improve _xxtestfuzz/README.rst #121024
• [3.13] gh-121023: Improve _xxtestfuzz/README.rst (GH-121024) #124140
• [3.12] gh-121023: Improve _xxtestfuzz/README.rst (GH-121024) #124141

[hugovk]

PR merged and backported 🚀