re PR c/38483 (generated aborts lose previous side-effects)
PR c/38483
* builtins.c (gimplify_va_arg_expr): Evaluate the va_list
expression before any __builtin_trap call.
* c-typeck.c (build_function_call): Convert and check function
arguments before generating a call to a trap. Evaluate the
function arguments before the trap.
testsuite:
* gcc.c-torture/execute/call-trap-1.c,
gcc.c-torture/execute/va-arg-trap-1.c, gcc.dg/call-diag-1.c: New
tests.