Rust: add warning to macro expansion integration test

Author: redsun82

rust/ql/integration-tests/macro-expansion/test.expected

@@ -37,3 +37,7 @@ unexpanded_macro_calls
 | calls/src/included.rs:2:9:2:39 | concat!... |
 | calls/src/lib.rs:22:9:22:31 | concat!... |
 | calls/src/lib.rs:29:9:29:32 | include_str!... |
+warnings
+| calls/src/included.rs:2:9:2:39 | macro expansion failed: could not resolve macro 'concat' |
+| calls/src/lib.rs:22:9:22:31 | macro expansion failed: could not resolve macro 'concat' |
+| calls/src/lib.rs:29:9:29:32 | macro expansion failed: could not resolve macro 'include_str' |

rust/ql/integration-tests/macro-expansion/test.ql

@@ -1,4 +1,5 @@
 import rust
+import codeql.rust.Diagnostics
 
 query predicate attribute_macros(Item i, int index, Item expanded) {
   i.fromSource() and expanded = i.getAttributeMacroExpansion().getItem(index)
@@ -13,3 +14,5 @@ query predicate macro_calls(MacroCall c, AstNode expansion) {
 query predicate unexpanded_macro_calls(MacroCall c) {
   c.fromSource() and not c.hasMacroCallExpansion()
 }
+
+query predicate warnings(ExtractionWarning w) { w.getLocation().fromSource() }