gdbstub: move chunk of softmmu functionality to own file

This is mostly code motion but a number of things needed to be done
for this minimal patch set:

  - move shared structures to internals.h
  - splitting some functions into user and softmmu versions
  - fixing a few casting issues to keep softmmu common

More CONFIG_USER_ONLY stuff will be handled in a following patches.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>

Message-Id: <20230302190846.2593720-11-alex.bennee@linaro.org>
Message-Id: <20230303025805.625589-11-richard.henderson@linaro.org>
diff --git a/gdbstub/trace-events b/gdbstub/trace-events
index 03f0c30..0c18a4d 100644
--- a/gdbstub/trace-events
+++ b/gdbstub/trace-events
@@ -7,7 +7,6 @@
 gdbstub_op_continue_cpu(int cpu_index) "Continuing CPU %d"
 gdbstub_op_stepping(int cpu_index) "Stepping CPU %d"
 gdbstub_op_extra_info(const char *info) "Thread extra info: %s"
-gdbstub_hit_watchpoint(const char *type, int cpu_gdb_index, uint64_t vaddr) "Watchpoint hit, type=\"%s\" cpu=%d, vaddr=0x%" PRIx64 ""
 gdbstub_hit_internal_error(void) "RUN_STATE_INTERNAL_ERROR"
 gdbstub_hit_break(void) "RUN_STATE_DEBUG"
 gdbstub_hit_paused(void) "RUN_STATE_PAUSED"
@@ -27,3 +26,6 @@
 gdbstub_err_invalid_rle(void) "got invalid RLE sequence"
 gdbstub_err_checksum_invalid(uint8_t ch) "got invalid command checksum digit: 0x%02x"
 gdbstub_err_checksum_incorrect(uint8_t expected, uint8_t got) "got command packet with incorrect checksum, expected=0x%02x, received=0x%02x"
+
+# softmmu.c
+gdbstub_hit_watchpoint(const char *type, int cpu_gdb_index, uint64_t vaddr) "Watchpoint hit, type=\"%s\" cpu=%d, vaddr=0x%" PRIx64 ""