Using symbolfile with cortexM3 results in illegal thumb->ARM32 trampoline

I am building code where the program resides in RAM but many functions reside in ROM.  Instead of using relocation, the program uses a symbolfile to specify function addresses in ROM.  A long-call is needed to access ROM from RAM.

If the compiler uses a long-call, everything works as expected, but if a short-call is made, the linker uses a thumb->ARM32 trampoline instead of a short-to-long call trampoline.

The cortexM3 architecture does not support ARM32, so the resulting binary is invalid.
test.c:
#pragma long_calls
extern void long_func();
#pragma no_long_calls
extern void short_func();

int main()
{
    long_func();
    short_func();
    return 0;
}

symbolfile:
long_func = 0x0801bbb1;
short_func = 0x0800717d;

compile via:
arm-none-eabi-gcc -mcpu=cortex-m3 -mthumb -Wall -Wextra -std=gnu99 -Os -c test.c
arm-none-eabi-ld test.o --just-symbols sym

The resulting disassembled code is:
a.out:     file format elf32-littlearm


Disassembly of section .text:

00008000 <main>:
    8000:	b508      	push	{r3, lr}
    8002:	4b03      	ldr	r3, [pc, #12]	; (8010 <main+0x10>)
    8004:	4798      	blx	r3
    8006:	f000 e808 	blx	8018 <__short_func_from_thumb>
    800a:	2000      	movs	r0, #0
    800c:	bd08      	pop	{r3, pc}
    800e:	bf00      	nop
    8010:	0801bbb1 	.word	0x0801bbb1
    8014:	00000000 	.word	0x00000000

00008018 <__short_func_from_thumb>:
    8018:	e51ff004 	ldr	pc, [pc, #-4]	; 801c <__short_func_from_thumb+0x4>
    801c:	0800717d 	.word	0x0800717d

As I work-around I found that I can use the following assembly code instead of a symbolfile:
        .global long_func
        .type long_func %function
        .equ    long_func, 0x0801bbb1

        .global short_func
        .type short_func %function
        .equ    short_func, 0x0800717d;

Which results in a short-to-long call veneer as expected.  Is this simply a case of symbolfiles not being supported with the cortexm3?  Or perhaps there is some way of indicating that the functions in the symbolfile are thumb?