Right after a "msr basepri_max, %[basepri]" instruction an interrupt
service may still take place (observed at least on Cortex-M7). However,
pendable service calls that are activated during this interrupt service
may be delayed until interrupts are enable again. The
_ARMV7M_Pendable_service_call() did not check that a thread dispatch is
allowed. Move this test from _ARMV7M_Interrupt_service_leave() to
_ARMV7M_Pendable_service_call().
Close#3060.
7e91901303