Ensure the definition of prvTaskExitError()does not result in a compiler warning in ports where its use can be overridden (GCC Cortex-M ports).

Remove duplicate save/restore of r14 in Cortex-M4F ports.

FreeRTOS/Source/portable/GCC/ARM_CM0/port.c

@@ -209,6 +209,12 @@ portBASE_TYPE xPortStartScheduler( void )
 	/* Start the first task. */
 	vPortStartFirstTask();
 	
+	/* Should never get here as the tasks will now be executing!  Call the task
+	exit error function to prevent compiler warnings about a static function
+	not being called in the case that the application writer overrides this
+	functionality by defining configTASK_RETURN_ADDRESS. */
+	prvTaskExitError();
+
 	/* Should not get here! */
 	return 0;
 }

FreeRTOS/Source/portable/GCC/ARM_CM3/port.c

@@ -329,6 +329,12 @@ portBASE_TYPE xPortStartScheduler( void )
 	/* Start the first task. */
 	prvPortStartFirstTask();
 
+	/* Should never get here as the tasks will now be executing!  Call the task
+	exit error function to prevent compiler warnings about a static function
+	not being called in the case that the application writer overrides this
+	functionality by defining configTASK_RETURN_ADDRESS. */
+	prvTaskExitError();
+
 	/* Should not get here! */
 	return 0;
 }

FreeRTOS/Source/portable/GCC/ARM_CM4F/port.c

@@ -353,6 +353,12 @@ portBASE_TYPE xPortStartScheduler( void )
 	/* Start the first task. */
 	prvPortStartFirstTask();
 
+	/* Should never get here as the tasks will now be executing!  Call the task
+	exit error function to prevent compiler warnings about a static function
+	not being called in the case that the application writer overrides this
+	functionality by defining configTASK_RETURN_ADDRESS. */
+	prvTaskExitError();
+
 	/* Should not get here! */
 	return 0;
 }
@@ -446,13 +452,13 @@ void xPortPendSVHandler( void )
 	"										\n"
 	"	str r0, [r2]						\n" /* Save the new top of stack into the first member of the TCB. */
 	"										\n"
-	"	stmdb sp!, {r3, r14}				\n"
+	"	stmdb sp!, {r3}						\n"
 	"	mov r0, %0 							\n"
 	"	msr basepri, r0						\n"
 	"	bl vTaskSwitchContext				\n"
 	"	mov r0, #0							\n"
 	"	msr basepri, r0						\n"
-	"	ldmia sp!, {r3, r14}				\n"
+	"	ldmia sp!, {r3}						\n"
 	"										\n"
 	"	ldr r1, [r3]						\n" /* The first item in pxCurrentTCB is the task top of stack. */
 	"	ldr r0, [r1]						\n"

FreeRTOS/Source/portable/IAR/ARM_CM4F/portasm.s

@@ -99,13 +99,13 @@ xPortPendSVHandler:
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	stmdb sp!, {r3, r14}
+	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	msr basepri, r0
 	bl vTaskSwitchContext
 	mov r0, #0
 	msr basepri, r0
-	ldmia sp!, {r3, r14}
+	ldmia sp!, {r3}
 
 	/* The first item in pxCurrentTCB is the task top of stack. */
 	ldr r1, [r3]

FreeRTOS/Source/portable/RVDS/ARM_CM4F/port.c

@@ -443,13 +443,13 @@ __asm void xPortPendSVHandler( void )
 	/* Save the new top of stack into the first member of the TCB. */
 	str r0, [r2]
 
-	stmdb sp!, {r3, r14}
+	stmdb sp!, {r3}
 	mov r0, #configMAX_SYSCALL_INTERRUPT_PRIORITY
 	msr basepri, r0
 	bl vTaskSwitchContext
 	mov r0, #0
 	msr basepri, r0
-	ldmia sp!, {r3, r14}
+	ldmia sp!, {r3}
 
 	/* The first item in pxCurrentTCB is the task top of stack. */
 	ldr r1, [r3]

FreeRTOS/Source/portable/Tasking/ARM_CM4F/port_asm.asm

@@ -89,13 +89,13 @@ _vector_14: .type func
 	;Save the new top of stack into the first member of the TCB.
 	str r0, [r2]
 
-	stmdb sp!, {r3, r14}
+	stmdb sp!, {r3}
 	ldr.w r0, =ulMaxSyscallInterruptPriorityConst
 	msr basepri, r0
 	bl vTaskSwitchContext
 	mov r0, #0
 	msr basepri, r0
-	ldmia sp!, {r3, r14}
+	ldmia sp!, {r3}
 
 	;The first item in pxCurrentTCB is the task top of stack.
 	ldr r1, [r3]
@@ -141,13 +141,13 @@ _lc_ref__vector_pp_14: .type func
 	;Save the new top of stack into the first member of the TCB.
 	str r0, [r2]
 
-	stmdb sp!, {r3, r14}
+	stmdb sp!, {r3}
 	ldr.w r0, =ulMaxSyscallInterruptPriorityConst
 	msr basepri, r0
 	bl vTaskSwitchContext
 	mov r0, #0
 	msr basepri, r0
-	ldmia sp!, {r3, r14}
+	ldmia sp!, {r3}
 
 	;The first item in pxCurrentTCB is the task top of stack.
 	ldr r1, [r3]