[mlir][SPIRV] Fix lookup logic spirv.target_env for gpu.module

The `gpu.module` operation can contain `spirv.target_env` attributes
within an array attribute named `"targets"`. So it accounts for that
case by iterating over the `"targets"` attribute, if present, and
looking up `spirv.target_env`.

Author: oojahooo

mlir/lib/Dialect/SPIRV/IR/TargetAndABI.cpp

@@ -184,6 +184,15 @@ spirv::TargetEnvAttr spirv::lookupTargetEnv(Operation *op) {
     if (!op)
       break;
 
+    if (auto arrAttr = op->getAttrOfType<ArrayAttr>("targets")) {
+      for (auto attr : arrAttr) {
+        if (auto spirvTargetEnvAttr =
+                llvm::dyn_cast<spirv::TargetEnvAttr>(attr)) {
+          return spirvTargetEnvAttr;
+        }
+      }
+    }
+
     if (auto attr = op->getAttrOfType<spirv::TargetEnvAttr>(
             spirv::getTargetEnvAttrName()))
       return attr;