Revised fix for bug 3111 - switch to usrt4_0.lib, which is exported unconditionally usrt3_1.lib is invisibly exported by an FLM, so in platform builds this failed with "No rule to make usrt3_1.dso"

EXPORTS
	Export1__Fv @ 1 NONAME ; Export1(void)
	Export2__Fv @ 2 NONAME ; Export2(void)
	Export3__Fv @ 3 NONAME ; Export3(void)
	Export4__Fv @ 4 NONAME ; Export4(void)