meson: move vector check inside of meson.build

It's three lines. There's no real reason to have this as a separate file
when we've removed every other compile check sourced from outside files.

meson.build

@@ -540,10 +540,12 @@ features += {'bsd-fstatfs': cc.has_function('fstatfs', prefix: '#include <sys/mo
 
 features += {'linux-fstatfs': cc.has_function('fstatfs', prefix: '#include <sys/vfs.h>')}
 
-fragments = join_paths(source_root, 'waftools', 'fragments')
-
+vector_attribute = '''int main() {
+float v __attribute__((vector_size(32)));
+}
+'''
 vector = get_option('vector').require(
-    cc.compiles(files(join_paths(fragments, 'vector.c')), name: 'vector check'),
+    cc.compiles(vector_attribute, name: 'vector check'),
     error_message: 'the compiler does not support gcc vectors!',
 )
 features += {'vector': vector.allowed()}

waftools/fragments/vector.c

@@ -1,4 +0,0 @@
-int main(int argc, char **argv) {
-    float v __attribute__((vector_size(32)));
-    return 0;
-}