pegtl: manage options to build examples and tests when run_tests (#21866)

Co-authored-by: Daryl W. Grunau <dwg@lanl.gov>

var/spack/repos/builtin/packages/pegtl/package.py

@@ -25,3 +25,25 @@ class Pegtl(CMakePackage):
 
     # Ref: https://github.com/taocpp/PEGTL/blob/master/src/example/pegtl/json_classes.hpp
     patch('change_to_virtual_destructor.patch', when='@:2.4')
+
+    def cmake_args(self):
+
+        args = []
+        if self.run_tests:
+            args.extend([
+                '-DPEGTL_BUILD_EXAMPLES=ON',
+                '-DPEGTL_BUILD_TESTS=ON'
+            ])
+        else:
+            args.extend([
+                '-DPEGTL_BUILD_EXAMPLES=OFF',
+                '-DPEGTL_BUILD_TESTS=OFF'
+            ])
+
+        return args
+
+    @run_after('build')
+    @on_package_attributes(run_tests=True)
+    def check(self):
+        with working_dir(self.build_directory):
+            make('test', parallel=False)