nasm test: Set the correct supported OSes for the tests
diff --git a/test cases/nasm/1 configure file/meson.build b/test cases/nasm/1 configure file/meson.build
index 85ecaf1..fac46a6 100644
--- a/test cases/nasm/1 configure file/meson.build
+++ b/test cases/nasm/1 configure file/meson.build
@@ -1,15 +1,17 @@
 project('nasm config file', 'c')
 
-if host_machine.cpu_family() == 'x86' and host_machine.system() == 'windows'
-  asm_format = 'win32'
-elif host_machine.cpu_family() == 'x86_64' and host_machine.system() == 'windows'
-  asm_format = 'win64'
-elif host_machine.cpu_family() == 'x86' and host_machine.system() == 'linux'
+if not host_machine.cpu_family().startswith('x86')
+  error('MESON_SKIP_TEST: nasm only supported for x86 and x86_64')
+endif
+
+if host_machine.system() != 'linux'
+  error('MESON_SKIP_TEST: this test asm is made for Linux')
+endif
+
+if host_machine.cpu_family() == 'x86'
   asm_format = 'elf32'
-elif host_machine.cpu_family() == 'x86_64' and host_machine.system() == 'linux'
-  asm_format = 'elf64'
 else
-  error('MESON_SKIP_TEST: skipping test on this platform')
+  asm_format = 'elf64'
 endif
 
 nasm = find_program('nasm', required: false)
diff --git a/test cases/nasm/2 asm language/meson.build b/test cases/nasm/2 asm language/meson.build
index d025d43..d5a2ba3 100644
--- a/test cases/nasm/2 asm language/meson.build
+++ b/test cases/nasm/2 asm language/meson.build
@@ -5,10 +5,8 @@
   error('MESON_SKIP_TEST: nasm only supported for x86 and x86_64')
 endif
 
-if host_machine.system() == 'windows'
-  error('MESON_SKIP_TEST: this test asm is not made for Windows')
-elif host_machine.system() == 'sunos'
-  error('MESON_SKIP_TEST: this test asm is not made for Solaris or illumos')
+if host_machine.system() != 'linux'
+  error('MESON_SKIP_TEST: this test asm is made for Linux')
 endif
 
 if meson.backend().startswith('vs')
diff --git a/test cases/nasm/3 nasm only/meson.build b/test cases/nasm/3 nasm only/meson.build
index 9777291..18b980d 100644
--- a/test cases/nasm/3 nasm only/meson.build
+++ b/test cases/nasm/3 nasm only/meson.build
@@ -4,6 +4,10 @@
   error('MESON_SKIP_TEST: nasm not found')
 endif
 
+if not ['linux', 'windows'].contains(host_machine.system())
+  error('MESON_SKIP_TEST: this test asm is made for Windows and Linux')
+endif
+
 if meson.backend().startswith('vs')
   error('MESON_SKIP_TEST: VS backend does not recognise NASM yet')
 endif