Building for ARM 32-bit embedded

[Bonsaipanda]

As a quick example, this is the output when building for armhf 
from Ubuntu >>
```
$ ldc2 -mtriple=armv6-linux-gnueabihf 
-gcc=arm-linux-gnueabihf-gcc -betterC test.d
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(4362): Error: 
none of the overloads of template 
`std.stdio.File.LockingTextWriter.put` are callable using 
argument types `!()(string)`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(3287):        
Candidates are: `put(A)(scope A writeme)`
   with `A = string`
   must satisfy one of the following constraints:
`       isSomeChar!(ElementType!A)
        is(ElementType!A : const(ubyte))`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(3317):        
                 `put(C)(scope C c)`
   with `C = string`
   must satisfy one of the following constraints:
`       isSomeChar!C
        is(C : const(ubyte))`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(3338): Error: 
none of the overloads of template `std.utf.decodeFront` are 
callable using argument types `!()(char[])`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/utf.d(1245):        
Candidates are: `decodeFront(Flag useReplacementDchar = 
No.useReplacementDchar, S)(ref S str, out size_t numCodeUnits)`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/utf.d(1285):          
               `decodeFront(Flag useReplacementDchar = 
No.useReplacementDchar, S)(ref scope S str, out size_t 
numCodeUnits)`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/utf.d(1314):          
               `decodeFront(Flag useReplacementDchar = 
No.useReplacementDchar, S)(ref S str)`
   with `useReplacementDchar = Flag.no,
        S = char[]`
   must satisfy the following constraint:
`       isInputRange!S`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/utf.d(2311): Error: 
cannot use `throw` statements with -betterC
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/utf.d(2514): Error: 
template instance `std.utf._utfException!Flag.no` error 
instantiating
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(3340):        
instantiated from here: `encode!Flag.no`
/usr/lib/ldc/x86_64-linux-gnu/include/d/std/stdio.d(4364):        
instantiated from here: `put!char`
test.d(3):        instantiated from here: `writeln!string`
```

If I didn't have CG to ask from, I wouldn't have had any idea 
what was happening and why are x86-64 components being called. I 
would even argue that it's LDC's job to make sure stuff, that the 
program is dependent on, gets built at the same time for the 
target. And I still don't understand why (core components?) like 
D runtime and Phobos are external libraries. But, such is life.