Support user-defined allocation functions

[ahueck]

TypeART should be configurable for user-defined allocation (and deallocation) functions

Consider the AMG multi grid solver.

AMG uses macros for memory allocation, e.g., a calloc-like implementation:

#define hypre_CTAlloc(type, count) \
( (type *)hypre_CAlloc((unsigned int)(count), (unsigned int)sizeof(type)) )

In turn the called function looks approximately like this:

char* hypre_CAlloc(int count, int elt_size) {
  char* ptr;
  int size = count * elt_size;

  ptr = calloc(count, elt_size);

  return ptr;
}

The defect:

Assume a call like:

 double* a = hypre_CTAlloc(double, num_variables);

1. Our static pass is not aware of this macro, it instead finds the C calloc.
2. Thus, it deduces the char* type for that calloc, which is put into our runtime.
3. The subsequent cast of the char* returned by hypre_CAlloc to double is not found by our current implementation.

[ahueck]

See also for support target: https://llvm.org/doxygen/MemAlloc_8h.html