Some initial work on support string literals

[robertoraggi]

Enough for

int puts(const char*);

int main() {
  char* s = "hello";
  puts(s);
  puts("hello");

  char a[10];
  a[0] = 'a';
  a[1] = 'b';
  a[2] = 'c';
  a[3] = '\0';
  puts(a);
  return 0;
}

$ cxx -c x.c -toolchain macos 

$ ld x.o -syslibroot /Library/Developer/CommandLineTools/SDKs/MacOSX15.sdk -lSystem

$ /a.out 

hello
hello
abc