optimize test_ct_intlog2 test and whirlpool hash (#2938)

* optimize `test_ct_intlog2` while still covering all 128 bit positions

* refactor whirlpool to reduce code bloat

replaced the fully unrolled round loop with a runtime loop, reducing
instruction count by 80k in `process_block` and yielding aprox 30%
performance boost due to improved cache locality.

* use compile-time arrays for `test_ct_intlog2`

benchmarks/stdlib/hash/whirlpool.c3

@@ -0,0 +1,57 @@
+module whirlpool_bench;
+
+fn void initialize_bench() @init
+{
+	set_benchmark_warmup_iterations(3);
+	set_benchmark_max_iterations(128);
+
+    input = mem::alloc_array(char, BUFSZ);
+    input[:BUFSZ] = (char[]){ [0..BUFSZ-1] = 0xA5 }[..];
+    input_slice = input[:BUFSZ];
+}
+
+fn void teardown_bench() @finalizer
+{
+    mem::free(input);
+    input = null;
+}
+
+char* input;
+char[] input_slice;
+const usz BUFSZ = 1024 * 1024;
+
+module whirlpool_bench @benchmark;
+
+import std::hash;
+
+fn void whirlpool_hash()
+{
+    runtime::@start_benchmark();
+    char[*] myset = whirlpool::hash(input_slice);
+    runtime::@end_benchmark();
+    mem::zero_volatile(myset[..]);
+}
+
+fn void compared_with_sha256()
+{
+    runtime::@start_benchmark();
+    char[*] myset = sha256::hash(input_slice);
+    runtime::@end_benchmark();
+    mem::zero_volatile(myset[..]);
+}
+
+fn void compared_with_sha512()
+{
+    runtime::@start_benchmark();
+    char[*] myset = sha512::hash(input_slice);
+    runtime::@end_benchmark();
+    mem::zero_volatile(myset[..]);
+}
+
+fn void compared_with_streebog_512()
+{
+    runtime::@start_benchmark();
+    char[*] myset = streebog::hash_512(input_slice);
+    runtime::@end_benchmark();
+    mem::zero_volatile(myset[..]);
+}