[clang-tidy] misc-include-cleaner false positives

[carlosgalvezp]

Take the following example code that implements the log2 function with a custom implementation:

constexpr int log2()
{
    int output = 0;
    return output;
}

clang-tidy trunk gives:

[<[source>:1:15: warning: no header providing "log2" is directly included [misc-include-cleaner]]
    1 | constexpr int log2()
      |               ^
[<source>:3:9: warning: no header providing "output" is directly included [misc-include-cleaner]]
    3 |     int output = 0;
      |         ^
2 warnings generated.

Which seems incorrect. Repro: https://godbolt.org/z/roM8E34ce

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Carlos Galvez (carlosgalvezp)

Take the following example code that implements the `log2` function with a custom implementation:

#include <cstdint>

constexpr uint32_t log2()
{
    uint32_t output = 0;
    return output;
}

clang-tidy trunk gives:

[<source>:3:20: warning: no header providing "log2" is directly included [misc-include-cleaner]]
    1 | #include <cstdint>
    2 | 
    3 | constexpr uint32_t log2()
      |                    ^
[<source>:5:14: warning: no header providing "output" is directly included [misc-include-cleaner]]
    5 |     uint32_t output = 0;
      |              ^
2 warnings generated.

Which seems incorrect. Repro: https://godbolt.org/z/vWoejee9v