craycc rejects the allocator modifier of the allocate clause

// # Draft finding: omp52-c-clause-allocate-allocator on cce19
//
// - compiler: cce19
// - toolchain: cce19; arch: gfx942; machine: tuolumne; memory mode: unified; opt: -O2
// - program: catalog omp52-c-clause-allocate-allocator (c, version 52, sha256 f3fb2637e316cfa9)
// - expected: None (None; )
// - actual: rejected  (diagnostic: <tmpdir>/omp52-c-clause-allocate-allocator.c:35:18: error: call to undeclared function 'allocator'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-dec)
// - verdict: compiler_bug by rule R11-compile-rejection: a legal program the compiler rejects with a diagnostic (or whose link fails on symbols the compiler's own code needs, or whose compile does not finish) while another compiler family compiles it
// - reason: 
// - citations: RUL-COMPILE-TIME (rulings.md)
// - legality: legal (legal by construction: offload.engine.gen / c_gen / acc_gen check every program against the catalog rules and the offload scope as it is built (no compiler))
// - witnesses: none
// - withdrawn: none
//
// Generated by compliance.c_gen (OpenMP 5.2, C11): the C port (offload.engine.f2c) of omp52-clause-allocate-allocator. Do not edit.
// id: omp52-c-clause-allocate-allocator
// primary atom: omp.clause.allocate.allocator
// legal: yes
// observable: no (unverified: the check covers the device kernel, not the atom)
// ran_on_host: inside the target region of interest
// evidence: unverified
// needs: none
// std: c11
// unverified (needs_other_infrastructure): the program cannot observe which allocator provides the private copy of t (no OpenMP routine reports a variable's allocator; omp_default_mem_alloc and the default allocator both return ordinary memory; C mutant survived on AFAR)
#include <stdio.h>
#include <stdbool.h>
#include <omp.h>

enum { n = 64 };

int main(void) {
  int a[n];
  int b[n];
  int ref[n];
  int host_flag;
  bool ok;
  int t;
  for (int i = 1; i <= n; i++) {
    a[i - 1] = i;
    b[i - 1] = 0;
    ref[i - 1] = 2 * i + 1;
  }
  host_flag = 1;
  #pragma omp target map(to: a) map(from: b) map(tofrom: host_flag) \
      uses_allocators(omp_default_mem_alloc)
  {
    host_flag = (omp_is_initial_device() ? 1 : 0);
    #pragma omp parallel for default(none) shared(a, b) private(t) \
        allocate(allocator(omp_default_mem_alloc): t)
    for (int i = 1; i <= n; i++) {
      t = 2 * a[i - 1];
      b[i - 1] = t + 1;
    }
  }
  bool t1_ = true;
  for (int k2_ = 0; k2_ < n; k2_++)
    t1_ = t1_ && (b[k2_] == ref[k2_]);
  ok = t1_;
  printf("RESULT ran_on_host=%d check=%s\n", host_flag, ok ? "pass" : "fail");
  return 0;
}
// spec (requirement): The allocate clause of OpenMP 5.2 accepts the allocator-complex-modifier form allocator(...),
//   with the syntax and semantics of the allocator clause.
// "The allocator-complex-modifier and align-modifier have the same syntax and semantics for the allocate clause as
//   the allocator and align clauses have for the allocate directive." (5.2 §6.6 p.178 l.16-18)
// spec (requirement): The allocator clause names the memory allocator used for allocations associated with the
//   construct.
// "The allocator clause specifies the memory allocator to be used for allocations associated with the construct on
//   which the clause appears." (5.2 §6.4 p.175 l.21-23)
// spec (this program): allocate(allocator(omp_default_mem_alloc): t) uses the complex-modifier spelling; craycc reads
//   allocator as a call to an undeclared function and rejects the clause, while the 5.0 spelling
//   allocate(omp_default_mem_alloc: t) is accepted.