address review, add invalid test for load frag a f64

Author: castigli

mlir/test/Target/LLVMIR/nvvmir-invalid.mlir

@@ -621,3 +621,14 @@ func.func @invalid_range_equal_bounds() {
   %0 = nvvm.read.ptx.sreg.warpsize range <i32, 32, 32> : i32
   return
 }
+
+// -----
+
+// Test for correct return type check for wmma.load fragment a for f64 
+llvm.func @nvvm_wmma_load_a_f64(%arg0: !llvm.ptr, %arg1 : i32) {
+  // expected-error @below {{'nvvm.wmma.load' op expected destination type to be f64}}
+  %0 = nvvm.wmma.load %arg0, %arg1
+    {eltype = #nvvm.mma_type<f64>, frag = #nvvm.mma_frag<a>, k = 4 : i32, layout = #nvvm.mma_layout<row>, m = 8 : i32, n = 8 : i32}
+    : (!llvm.ptr) -> !llvm.struct<(f64)>
+  llvm.return
+}