target/tcl: Add set_reg function

Change-Id: I97a01b93046cb7af289792489f77f5580312585a
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/5313
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

doc/openocd.texi

@@ -5003,6 +5003,21 @@ and neither store nor return those values.
 @end itemize
 @end deffn
 
+@deffn {Command} {$target_name set_reg} dict
+Set register values of the target.
+
+@itemize
+@item @var{dict} ... Tcl dictionary with pairs of register names and values.
+@end itemize
+
+For example, the following command sets the value 0 to the program counter (pc)
+register and 0x1000 to the stack pointer (sp) register:
+
+@example
+set_reg @{pc 0 sp 0x1000@}
+@end example
+@end deffn
+
 @deffn {Command} {$target_name cget} queryparm
 Each configuration parameter accepted by
 @command{$target_name configure}
@@ -8491,6 +8506,21 @@ Debug and trace infrastructure:
 @end example
 @end deffn
 
+@deffn {Command} {set_reg} dict
+Set register values of the target.
+
+@itemize
+@item @var{dict} ... Tcl dictionary with pairs of register names and values.
+@end itemize
+
+For example, the following command sets the value 0 to the program counter (pc)
+register and 0x1000 to the stack pointer (sp) register:
+
+@example
+set_reg @{pc 0 sp 0x1000@}
+@end example
+@end deffn
+
 @deffn {Command} {halt} [ms]
 @deffnx {Command} {wait_halt} [ms]
 The @command{halt} command first sends a halt request to the target,