Background:

• A list of libc builtins (for operations with memory and strings) should be supported: #I3ZSKS:mapleC builtin support
• Required changes for backend / middle end and FEIR were added by previously merged PRs #1063,#1076.
• This PR contains the code of HIR2MPL implementation of builtins emitting via intrinsicop/intrinsiccall.

Solution:

I. From AST to FEIR:

1. intrinsics for libc functions derived as operations (no side effects) from UniqueFEIRExpr by CreateIntrinsicOpForC:
   INTRN_C_memcmp
   INTRN_C_strlen
   INTRN_C_strcmp
   INTRN_C_strncmp
   INTRN_C_strchr
   INTRN_C_strrchr

2. intrinsics for libc functions derived as intrinsiccalls from UniqueFEIRExpr by CreateIntrinsicCallForC function (also added in this PR):
   INTRN_C_memcpy;
   INTRN_C_memmove;
   INTRN_C_memset;
   INTRN_C_strcpy;
   INTRN_C_strncpy;

I*. Intrinsics emit refactoring:

New macro for intrinsics emit are added for more convenient way of default emitter of intrinsic call/op function registration: DEF_INTRIN_C_CALL and DEF_INTRIN_C_OP.

II. Sanity tests (SANITY0043-64) are added for builtins testing.