swift: Support swift_args

Fixes #12533

mesonbuild/backend/ninjabackend.py

@@ -2172,6 +2172,7 @@ class NinjaBackend(backends.Backend):
                 srctreedir = os.path.normpath(os.path.join(self.environment.get_build_dir(), self.build_to_src, expdir))
                 sargs = swiftc.get_include_args(srctreedir, False)
                 compile_args += sargs
+        compile_args += target.get_extra_args('swift')
         link_args = swiftc.get_output_args(os.path.join(self.environment.get_build_dir(), self.get_target_filename(target)))
         link_args += self.build.get_project_link_args(swiftc, target.subproject, target.for_machine)
         link_args += self.build.get_global_link_args(swiftc, target.for_machine)

test cases/swift/8 extra args/main.swift

@@ -0,0 +1 @@
+print("test")

test cases/swift/8 extra args/meson.build

@@ -0,0 +1,18 @@
+project('extra args', 'swift')
+
+trace_fname = 'trace.json'
+
+lib = static_library('main',
+  'main.swift',
+  swift_args: [
+    '-emit-loaded-module-trace',
+    '-emit-loaded-module-trace-path', '../' + trace_fname
+  ],
+)
+
+custom_target('trace_check',
+  output: trace_fname,
+  command: ['cat', '@OUTPUT@'],
+  depends: lib,
+  build_always: true,
+)