lit tests: Drop support for gdb < 8 and dependency on distutils pip p…

…ackage

Fixes ldc-developers#4671.

tests/debuginfo/print_gdb.d

@@ -1,5 +1,3 @@
-// REQUIRES: atleast_gdb80
-
 // This test fails due to newer version of GDB, see https://github.com/ldc-developers/ldc/issues/4389
 // XFAIL: FreeBSD
 

tests/lit.site.cfg.in

@@ -7,7 +7,6 @@ import string
 import re
 import subprocess
 import glob
-from distutils.version import LooseVersion
 
 # Cmake Boolean options
 ON = True
@@ -203,19 +202,14 @@ if (platform.system() == 'Windows') and os.path.isfile( cdb ):
 # Check whether GDB is present
 if (platform.system() != 'Windows') and lit.util.which('gdb', config.environment['PATH']):
     config.available_features.add('gdb')
-    gdb_dflags = ''
-    command = ['gdb', '--version']
-    p = subprocess.Popen(command, stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE, universal_newlines=True)
-    text = p.stdout.readline()
-    m = re.compile('[^0-9]*([0-9]+[0-9.]*).*').match(text)
-    if m is not None:
-        gdb_version = m.group(1)
-        if LooseVersion(gdb_version) < LooseVersion('7.8'):
-            gdb_dflags = '-dwarf-version=2'
-        elif LooseVersion(gdb_version) >= LooseVersion('8.0'):
-            config.available_features.add('atleast_gdb80')
-
+    gdb_dflags = '' # for gdb-version-dependant flags
+    #command = ['gdb', '--version']
+    #p = subprocess.Popen(command, stdout=subprocess.PIPE,
+    #        stderr=subprocess.PIPE, universal_newlines=True)
+    #text = p.stdout.readline()
+    #m = re.compile('[^0-9]*([0-9]+[0-9.]*).*').match(text)
+    #if m is not None:
+    #    gdb_version = m.group(1)
     config.substitutions.append( ('%_gdb_dflags', gdb_dflags) )
 
 if 'LD_LIBRARY_PATH' in os.environ: