fatal error: too many errors emitted, stopping now [-ferror-limit=] 20 errors generated. 20 errors generated. 20 errors generated. 20 errors generated. lld-link: error: build\arena.obj: machine type x86 conflicts with x64 lld-link: error: build\atoms.obj: machine type x86 conflicts with x64 lld-link: error: build\big_array.obj: machine type x86 conflicts with x64 lld-link: error: build\crash_handler.obj: machine type x86 conflicts with x64 lld-link: error: build\diagnostic.obj: machine type x86 conflicts with x64 lld-link: error: build\lexer.obj: machine type x86 conflicts with x64 lld-link: error: build\linker.obj: machine type x86 conflicts with x64 lld-link: error: build\microsoft_craziness.obj: machine type x86 conflicts with x64 lld-link: error: build\tblink.obj: machine type x86 conflicts with x64 lld-link: error: build\threads_msvc.obj: machine type x86 conflicts with x64 lld-link: error: build\tls.obj: machine type x86 conflicts with x64 lld-link: error: could not open 'ole32.lib': no such file or directory lld-link: error: could not open 'Advapi32.lib': no such file or directory lld-link: error: could not open 'OleAut32.lib': no such file or directory lld-link: error: could not open 'DbgHelp.lib': no such file or directory lld-link: error: could not open 'libcmt.lib': no such file or directory

Changes:

1. If the user who is compiling Cuik already has vcvars set, vcvars won't need to be initialized again. Helps with extra error message like "vcvars not found" in case of Visual Studio Developer Prompt that doesn't keep vcvars in it's PATH by default.
2. If vcvars weren't found in PATH a nice error message is displayed telling the user to either add it to PATH or use the Visual Studio Develeoper Command Prompt.
3. /Z7 doesn't emit an extra pdb (that's not essential for normal debugging) also fuck visual studio
4. Fixed a case of UB on calling strcmp with NULL argument that would trigger a crash on Windows if the argument to an option is not specified.

When compiling with MSVC, cc_command doesn't isn't declared. This PR adds a declaration with a default value of 0. This function isn't called when compiling with MSVC, but it still blocks compiling compile.c

Test case:

struct Expr typedef Expr;
struct Expr {
    Expr *car;
    Expr *cdr;
};

#define      car(expr) expr->car
#define      cdr(expr) expr->cdr

void x(Expr *args)
{
    car(cdr(cdr(args)));
}

MSVC and Cland expand macro, as expected, to expr->cdr->cdr->car. Cuik however prints the following error message:

$ cuik build code\test.c
error: code\test.c:13:0: could not resolve symbol: cdr
    13| cdr(args) -> cdr
      | ^~~
exited with 1 error

When I try to compile my project with cuik I get an error on the following line:

    return make_bool(isinf(f1));

Note the isinf function, which is a standard library function. The error says:

error: C:/programs/blisp/code/wrap.c:261:0: Could not parse expression!
   261| _Pragma ( "warning ( suppress : 6334 )" )
      | ^~~~~~~

The help message for cuik lists "help" as one of the valid commands, however when I try to run cuik it says "help" is an unkown command ("I have never seen this man before")

$ cuik help
Unknown command: help

As a side not i'd like for a way to look up information about various flags and options available in the compiler