IMPORTANT

1. You have verified that the issue to be present in the current dev branch.

• ye

2. Please supply the command line options and relevant environment variables,
   e.g., a copy-paste of the contents of out/default/fuzzer_setup..

• not even starting the fuzzer, N/A

Describe the bug
If a function contains a std::string/std::list parameter (or template class referencing those types), the function is not instrumented.

To Reproduce
Steps to reproduce the behavior:

1. Build AFL++. The system compiler should use libstdc++ by default (which is the case on most linux distros).
2. Create the following file:

#include <cstdio>
#include <string>

#ifdef I_WANNA_DIE
typedef std::string Param;
#else
typedef int Param;
#endif

int g;

void func(Param p) {
  if (g) { // this probably should create coverage...
    printf("foo");
  }
}

3. Compile it with ./AFLplusplus/afl-clang-fast++ path/to/file.cpp to see AFL++ would instrument this.
4. Run ./AFLplusplus/afl-clang-fast++ path/to/file.cpp -DI_WANNA_DIE=1 and it no longer instruments it.

$ ./AFLplusplus/afl-clang-fast++ what-the-fuck.cpp -o /dev/null -c
afl-cc++4.09a by Michal Zalewski, Laszlo Szekeres, Marc Heuse - mode: LLVM-PCGUARD
SanitizerCoveragePCGUARD++4.09a
[+] Instrumented 3 locations with no collisions (non-hardened mode) of which are 0 handled and 0 unhandled selects.
$ ./AFLplusplus/afl-clang-fast++ -DI_WANNA_DIE=1 what-the-fuck.cpp -o /dev/null -c
afl-cc++4.09a by Michal Zalewski, Laszlo Szekeres, Marc Heuse - mode: LLVM-PCGUARD
SanitizerCoveragePCGUARD++4.09a
[!] WARNING: No instrumentation targets found.

Expected behavior
It probably should instrument the function.

Additional context
The function isIgnoreFunction in instrumentation/afl-llvm-common.cc contains the following code which seems to filter all these functions out because std::string is mangled as St7__cxx1112basic_string... with libstdc++ (the __cxx is the relevant substring).

  static constexpr const char *ignoreSubstringList[] = {

      "__asan", "__msan",       "__ubsan",    "__lsan",  "__san", "__sanitize",
      "__cxx",  "DebugCounter", "DwarfDebug", "DebugLoc"

  };

  for (auto const &ignoreListFunc : ignoreSubstringList) {

    // hexcoder: F->getName().contains() not avaiilable in llvm 3.8.0
    if (StringRef::npos != F->getName().find(ignoreListFunc)) { return true; }

  }

TLDR: Filtering based on whether function name contains __cxx is skipping everything that referenced std::string/list in the mangled name.