static variable __StackTop cannot be read at compile time even if extern?

[Taylor Hillegeist via digitalmars-d-ldc]

So I'm trying to get my FRDM-KL25Z (cortex-m0) board up and 
running. I've got minimal c code running and trying to do a 
direct conversion for a start. I'm using LDC for this project.

The linker Describes the symbol __StackTop
This is very nice and useful.

So i have this code:

extern(C) int __StackTop;

@attribute("section",".isr_vector")
shared ISR[3] g_pfnVectors  =
[
     __StackTop,
     Reset_Handler,
     ....

However I keep getting:
start.d(62): Error: static variable __StackTop cannot be read at 
compile time

I need the symbol to be ignored until linking. How do i do it?