all: Update reserved function names

Update reserved function names starting with one underscore, replacing
them as follows:
   '_k_' with 'z_'
   '_K_' with 'Z_'
   '_handler_' with 'z_handl_'
   '_Cstart' with 'z_cstart'
   '_Swap' with 'z_swap'

This renaming is done on both global and those static function names
in kernel/include and include/. Other static function names in kernel/
are renamed by removing the leading underscore. Other function names
not starting with any prefix listed above are renamed starting with
a 'z_' or 'Z_' prefix.

Function names starting with two or three leading underscores are not
automatcally renamed since these names will collide with the variants
with two or three leading underscores.

Various generator scripts have also been updated as well as perf,
linker and usb files. These are
   drivers/serial/uart_handlers.c
   include/linker/kobject-text.ld
   kernel/include/syscall_handler.h
   scripts/gen_kobject_list.py
   scripts/gen_syscall_header.py

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>

drivers/hwinfo/hwinfo_handlers.c

@@ -11,5 +11,5 @@ Z_SYSCALL_HANDLER(hwinfo_get_device_id, buffer, length) {
 
 	Z_OOPS(Z_SYSCALL_MEMORY_WRITE(buffer, length));
 
-	return _impl_hwinfo_get_device_id((u8_t *)buffer, (size_t)length);
+	return z_impl_hwinfo_get_device_id((u8_t *)buffer, (size_t)length);
 }

drivers/hwinfo/hwinfo_imxrt.c

@@ -12,7 +12,7 @@ struct imxrt_uid {
 	u32_t id[2];
 };
 
-ssize_t _impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
+ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct imxrt_uid dev_id;
 

drivers/hwinfo/hwinfo_mcux_sim.c

@@ -28,7 +28,7 @@ struct kinetis_uid {
 	u32_t id[HWINFO_DEVICE_ID_LENGTH_TOTAL];
 };
 
-ssize_t _impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
+ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct kinetis_uid dev_id;
 

drivers/hwinfo/hwinfo_nrf.c

@@ -12,7 +12,7 @@ struct nrf_uid {
 	u32_t id[2];
 };
 
-ssize_t _impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
+ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct nrf_uid dev_id;
 

drivers/hwinfo/hwinfo_stm32.c

@@ -12,7 +12,7 @@ struct stm32_uid {
 	u32_t id[3];
 };
 
-ssize_t _impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
+ssize_t z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	struct stm32_uid dev_id;
 

drivers/hwinfo/hwinfo_weak_impl.c

@@ -6,7 +6,7 @@
 
 #include <hwinfo.h>
 
-ssize_t __weak _impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
+ssize_t __weak z_impl_hwinfo_get_device_id(u8_t *buffer, size_t length)
 {
 	return -ENOTSUP;
 }