tests: nasm: make it easier to debug generator() style build

By default, we build with debug info which can be useful for
investigating why a test segfaults instead of either passing or failing.
The nasm language hooks this up, but using nasm as a generator program
does not.

Bug: https://bugs.gentoo.org/936911

test cases/nasm/1 configure file/meson.build

@@ -24,10 +24,16 @@ conf = configuration_data()
 
 conf.set('HELLO', 0)
 
+debug_nasm = []
+if get_option('debug')
+  debug_nasm = ['-g']
+endif
+
 asm_gen = generator(nasm,
   output : '@BASENAME@.o',
   arguments : [
     '-f', asm_format,
+    debug_nasm,
     '-i', meson.current_source_dir() + '/',
     '-i', join_paths(meson.current_source_dir(), ''),
     '-P', join_paths(meson.current_build_dir(), 'config.asm'),