backends: move method from ninjabackend to base class

The baseclass has code that assumes said method exists, and it really
doesn't seem to do anything ninja specific, so move it to the generic
backend.

mesonbuild/backend/backends.py

@@ -789,16 +789,21 @@ class Backend:
         return pch_rel_to_build
 
     @staticmethod
-    def escape_extra_args(compiler, args):
+    def escape_extra_args(args: T.List[str]) -> T.List[str]:
         # all backslashes in defines are doubly-escaped
-        extra_args = []
+        extra_args: T.List[str] = []
         for arg in args:
-            if arg.startswith('-D') or arg.startswith('/D'):
+            if arg.startswith(('-D', '/D')):
                 arg = arg.replace('\\', '\\\\')
             extra_args.append(arg)
 
         return extra_args
 
+    def get_no_stdlib_args(self, target: 'build.BuildTarget', compiler: 'Compiler') -> T.List[str]:
+        if compiler.language in self.build.stdlibs[target.for_machine]:
+            return compiler.get_no_stdinc_args()
+        return []
+
     def generate_basic_compiler_args(self, target: build.BuildTarget, compiler: 'Compiler', no_warn_args: bool = False) -> 'CompilerArgs':
         # Create an empty commands list, and start adding arguments from
         # various sources in the order in which they must override each other

mesonbuild/backend/ninjabackend.py

@@ -2313,11 +2313,6 @@ https://gcc.gnu.org/bugzilla/show_bug.cgi?id=47485'''))
         mod_files = _scan_fortran_file_deps(src, srcdir, dirname, tdeps, compiler)
         return mod_files
 
-    def get_no_stdlib_args(self, target, compiler):
-        if compiler.language in self.build.stdlibs[target.for_machine]:
-            return compiler.get_no_stdinc_args()
-        return []
-
     def get_no_stdlib_link_args(self, target, linker):
         if hasattr(linker, 'language') and linker.language in self.build.stdlibs[target.for_machine]:
             return linker.get_no_stdlib_link_args()