[COMMITTED] gccrs: attributes: Add #[macro_use] as builtin

[Arthur Cohen <arthur.cohen@embecosm.com>]

gcc/rust/ChangeLog:

	* util/rust-attributes.cc: Add `macro_use` to list of builtin
	attributes.

gcc/testsuite/ChangeLog:

	* rust/compile/macro_export_1.rs: New test.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/rust/util/rust-attributes.cc             | 1 +
 gcc/testsuite/rust/compile/macro_export_1.rs | 2 ++
 2 files changed, 3 insertions(+)
 create mode 100644 gcc/testsuite/rust/compile/macro_export_1.rs

diff --git a/gcc/rust/util/rust-attributes.cc b/gcc/rust/util/rust-attributes.cc
index 9db77b40dfb..1c85273e541 100644
--- a/gcc/rust/util/rust-attributes.cc
+++ b/gcc/rust/util/rust-attributes.cc
@@ -40,6 +40,7 @@ static const BuiltinAttrDefinition __definitions[]
      {"no_mangle", CODE_GENERATION},
      {"repr", CODE_GENERATION},
      {"path", EXPANSION},
+     {"macro_use", NAME_RESOLUTION},
      // From now on, these are reserved by the compiler and gated through
      // #![feature(rustc_attrs)]
      {"rustc_inherit_overflow_checks", CODE_GENERATION}};
diff --git a/gcc/testsuite/rust/compile/macro_export_1.rs b/gcc/testsuite/rust/compile/macro_export_1.rs
new file mode 100644
index 00000000000..f87df083624
--- /dev/null
+++ b/gcc/testsuite/rust/compile/macro_export_1.rs
@@ -0,0 +1,2 @@
+#[macro_use]
+mod foo {}
-- 
2.39.1