RTS: Use ELF v1 convention on all powerpc64 systems

rts/StgCRun.c

@@ -719,7 +719,6 @@ StgRunIsImplementedInAssembler(void)
 
 #if defined(powerpc64_HOST_ARCH)
 
-#if defined(linux_HOST_OS)
 static void GNUC3_ATTRIBUTE(used)
 StgRunIsImplementedInAssembler(void)
 {
@@ -841,10 +840,6 @@ StgRunIsImplementedInAssembler(void)
         : : "i"(RESERVED_C_STACK_BYTES+304 /*stack frame size*/));
 }
 
-#else // linux_HOST_OS
-#error Only Linux support for power64 right now.
-#endif
-
 #endif
 
 #if defined(powerpc64le_HOST_ARCH)