Add include guards and memory allocation wrappers that can be overwri…

[mingodad]

…tten by end users

[mingodad]

Doing this I realized that we are very confident that memory allocation will never fail !

[ChrisHixon]

This is incomplete in the bootstrap dir:

% grep malloc peg_cbyte.c    
    res = (unsigned char *)malloc(len + 1);
    Node *self = (Node *)malloc(sizeof(Node));
    Parser *self = (Parser *)malloc(sizeof(Parser));
    ByteCode *self = (ByteCode *)malloc(sizeof(ByteCode));

Fails to make in examples after bootstrap:

# bootstrap:
[~/Projects/GitHub/chpeg/bootstrap]% ./generate_src_files

# make in examples:
[~/Projects/GitHub/chpeg/examples]% make clean; make
rm -rf obj
rm -rf chpeg
rm peg_parse_file
rm: cannot remove 'peg_parse_file': No such file or directory
make: [Makefile:50: clean] Error 1 (ignored)
mkdir obj
mkdir chpeg
gcc -c -Wall -std=c99 -O3 ../src/peg_cbyte_parser.c -o chpeg/peg_cbyte_parser.o
In file included from ../src/peg_cbyte_parser.c:4:
../src/peg_cbyte_parser.h:222:2: error: #endif without #if
  222 | #endif //PEG_CBYTE_PARSER_H
      |  ^~~~~
make: *** [Makefile:41: chpeg/peg_cbyte_parser.o] Error 1

[mingodad]

My fault I forgot to add the open include guard on the bootstrap template, I think that's fixed now.