gdb/{testsuite,system-gdbinit}: import gdb module in Python scripts

Fix flake8 warnings like:

    gdb/system-gdbinit/wrs-linux.py:21:5: F821 undefined name 'gdb'

These scripts get executed in a context where the gdb module is already
loaded, so this is not strictly necessary.  However, adding these
imports removes a lot of red lines when editing these files in an IDE.
Without them, the code uses this `gdb` thing that appears to be
undefined.  Pylance is able to pull the module definition from typeshed
[1] and provide a good experience with typings.

[1] https://github.com/python/typeshed/tree/main/stubs/gdb/gdb

Change-Id: I09c6ae1866ef66f10d8270457771687343c84e32
Approved-By: Tom Tromey <tom@tromey.com>

gdb/system-gdbinit/wrs-linux.py

@@ -17,6 +17,8 @@
 
 import os
 
+import gdb
+
 if "ENV_PREFIX" in os.environ:
     gdb.execute("set sysroot %s" % os.environ["ENV_PREFIX"])
 

gdb/testsuite/gdb.base/bp-disabled-by-cond.py

@@ -12,6 +12,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import gdb
 
 bp_modified_list = []
 

gdb/testsuite/gdb.base/frame-view.py

@@ -12,6 +12,7 @@
 #
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
+import gdb
 
 
 class Printer1:

gdb/testsuite/gdb.base/reset-catchpoint-cond.py

@@ -13,6 +13,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import gdb
+
 bp_modified_list = []
 
 

gdb/testsuite/gdb.base/shlib-unload.py

@@ -13,6 +13,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import gdb
+
 # Breakpoint modification events will be recorded in this dictionary.
 # The keys are the b/p numbers, and the values are the number of
 # modification events seen.

gdb/testsuite/gdb.perf/backtrace.py

@@ -15,6 +15,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class BackTrace(perftest.TestCaseWithBasicMeasurements):
     def __init__(self, depth):

gdb/testsuite/gdb.perf/disassemble.py

@@ -15,6 +15,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class Disassemble(perftest.TestCaseWithBasicMeasurements):
     def __init__(self):

gdb/testsuite/gdb.perf/single-step.py

@@ -15,6 +15,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class SingleStep(perftest.TestCaseWithBasicMeasurements):
     def __init__(self, step):

gdb/testsuite/gdb.perf/skip-command.py

@@ -15,6 +15,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class SkipCommand(perftest.TestCaseWithBasicMeasurements):
     def __init__(self, name, step):

gdb/testsuite/gdb.perf/skip-prologue.py

@@ -18,6 +18,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class SkipPrologue(perftest.TestCaseWithBasicMeasurements):
     def __init__(self, count):

gdb/testsuite/gdb.perf/solib.py

@@ -18,6 +18,8 @@
 
 from perftest import measure, perftest
 
+import gdb
+
 
 class SolibLoadUnload1(perftest.TestCaseWithBasicMeasurements):
     def __init__(self, solib_count, measure_load):

gdb/testsuite/gdb.perf/template-breakpoints.py

@@ -15,6 +15,8 @@
 
 from perftest import perftest
 
+import gdb
+
 
 class TemplateBreakpoints(perftest.TestCaseWithBasicMeasurements):
     def __init__(self):

gdb/testsuite/gdb.python/pretty-print-call-by-hand.py

@@ -14,6 +14,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import gdb
+
+
 class MytypePrinter:
     """pretty print my type"""
 

gdb/testsuite/gdb.python/py-auto-load-chaining-f1.o-gdb.py

@@ -18,6 +18,8 @@
 
 import re
 
+import gdb
+
 print("Entering f1.o auto-load script")
 
 print("Current objfile is: %s" % gdb.current_objfile().filename)

gdb/testsuite/gdb.python/py-auto-load-chaining-f2.o-gdb.py

@@ -16,6 +16,8 @@
 # This script is auto-loaded when the py-auto-load-chaining-f2.o
 # object is loaded.
 
+import gdb
+
 print("Entering f2.o auto-load script")
 
 print("Current objfile is: %s" % gdb.current_objfile().filename)

gdb/testsuite/gdb.python/py-color-leak.py

@@ -15,6 +15,8 @@
 
 import sys
 
+import gdb
+
 # Avoid generating
 # src/gdb/testsuite/gdb.python/__pycache__/gdb_leak_detector.cpython-<n>.pyc.
 sys.dont_write_bytecode = True

gdb/testsuite/gdb.python/py-corefile.py

@@ -15,6 +15,8 @@
 
 import pathlib
 
+import gdb
+
 
 class Mapping:
     def __init__(self, mapping, region):

gdb/testsuite/gdb.python/py-finish-breakpoint-deletion.py

@@ -14,6 +14,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import gdb
+
+
 class MyFinishBreakpoint(gdb.FinishBreakpoint):
     def stop(self):
         print("stopped at MyFinishBreakpoint")

gdb/testsuite/gdb.python/py-finish-breakpoint.py

@@ -17,6 +17,9 @@
 # Breakpoints.
 
 
+import gdb
+
+
 class MyFinishBreakpoint(gdb.FinishBreakpoint):
     def __init__(self, val, frame):
         gdb.FinishBreakpoint.__init__(self, frame)

gdb/testsuite/gdb.python/py-finish-breakpoint2.py

@@ -16,6 +16,8 @@
 # This file is part of the GDB testsuite.  It tests python Finish
 # Breakpoints.
 
+import gdb
+
 
 class ExceptionFinishBreakpoint(gdb.FinishBreakpoint):
     def __init__(self, frame):

gdb/testsuite/gdb.python/py-inferior-leak.py

@@ -15,6 +15,8 @@
 
 import sys
 
+import gdb
+
 # Avoid generating
 # src/gdb/testsuite/gdb.python/__pycache__/gdb_leak_detector.cpython-<n>.pyc.
 sys.dont_write_bytecode = True

gdb/testsuite/gdb.python/py-objfile-script-gdb.py

@@ -17,6 +17,8 @@
 
 import re
 
+import gdb
+
 
 class pp_ss:
     def __init__(self, val):

gdb/testsuite/gdb.python/py-read-memory-leak.py

@@ -15,6 +15,8 @@
 
 import sys
 
+import gdb
+
 # Avoid generating
 # src/gdb/testsuite/gdb.python/__pycache__/gdb_leak_detector.cpython-<n>.pyc.
 sys.dont_write_bytecode = True

gdb/testsuite/gdb.python/py-section-script.py

@@ -17,6 +17,8 @@
 
 import re
 
+import gdb
+
 
 class pp_ss:
     def __init__(self, val):

gdb/testsuite/gdb.python/py-watchpoint.py

@@ -14,6 +14,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import gdb
+
+
 class MyBreakpoint(gdb.Breakpoint):
     def __init__(self):
         super().__init__("i", gdb.BP_WATCHPOINT)

gdb/testsuite/gdb.python/tui-window-factory.py

@@ -14,6 +14,9 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import gdb
+
+
 class TestWindow:
     def __init__(self, tui_win, msg):
         self.msg = msg

gdb/testsuite/gdb.server/fileio-packets.py

@@ -16,6 +16,8 @@
 import os
 import stat
 
+import gdb
+
 
 # Hex encode INPUT_STRING in the same way that GDB does.  Each
 # character in INPUT_STRING is expanded to its two digit hex