Add -Z llvm_module_flag

Allow adding values to the `!llvm.module.flags` metadata for a generated
module.  The syntax is

`-Z llvm_module_flag=<name>:<type>:<value>:<behavior>`

Currently only u32 values are supported but the type is required to be
specified for forward compatibility.  The `behavior` element must match
one of the named LLVM metadata behaviors.viors.

This flag is expected to be perma-unstable.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/codegen/llvm_module_flags.rs b/tests/codegen/llvm_module_flags.rs
new file mode 100644
index 00000000000..acc035086de
--- /dev/null
+++ b/tests/codegen/llvm_module_flags.rs
@@ -0,0 +1,7 @@
+// Test for -Z llvm_module_flags
+// compile-flags: -Z llvm_module_flag=foo:u32:123:error -Z llvm_module_flag=bar:u32:42:max
+
+fn main() {}
+
+// CHECK: !{i32 1, !"foo", i32 123}
+// CHECK: !{i32 7, !"bar", i32 42}