Fix up some cases of Byval As String in examples/headers

For none of these it really mattered though:

For the examples the WinMain() declarations didn't match the Win32 API but
since they're not never used as entry point but instead only used
internally, it didn't really matter.

And the X11 headers were just mistranslated, and are still not ready (won't
even compile), so it doesn't really matter there either.
C backend: Simplify typeCBop()
symb: Add FBSYMCHAIN dumping function for debugging
Add crt/longdouble.bi for providing CLONGDOUBLE to bindings
tests: Add some tests for array subscripts
Unix rtlib: Call pthread_attr_destroy() in fb_ThreadCreate()

Corresponding to every pthread_attr_init() there should be a
pthread_attr_destroy(). Note: pthread_create() doesn't "take ownership"
of the attr object, so the caller is supposed to free it.

I don't know whether this makes any real difference here for us, it also
depends on the pthreads implementation, but it should be safer this way.
frontend: Fix -arch native to work as intended with -gen gcc again
frontend: Rename fbCpuTypeIs64bit() to just fbIs64bit()
frontend: Remove unused FB_CPUTYPE_* constants
frontend: Remove FB_HOST_BITS and add fbGetBits() and fbGetHostBits() helpers
frontend: Remove FB_HOST_TARGETID and add fbGetHostId() helper
frontend: Store arch dir prefixes in cputypeinfo() table
frontend: Only store gccarch name in cputypeinfo() where <> fbcarch name

(saves nothing but improves readability, of the table at least)
frontend: Add fbGetCpuFamily() and FB_CPUFAMILY_*, replace fbCpuTypeIsX86()
frontend: Only pass -m32/-m64 to gcc on x86/x86_64

(gcc doesn't support these options on other archs)
frontend: Only pass --32/--64 to GAS on x86/x86_64

(GAS doesn't support these options on other archs)
frontend: For llc, only use --x86-asm-syntax=intel on x86/x86_64
frontend: Check x86/x86_64 instead of 32bit/64bit where intended
frontend: Simplify -target parsing
makefile: Fix formatting