Fix use of integer constants with float16 types

This generate warnings on MSVC (and probably other compilers too).

PiperOrigin-RevId: 728489631

Author: dsharletg

test/convolution-operator-tester.h

@@ -1021,7 +1021,7 @@ class ConvolutionOperatorTester {
         std::unique_ptr<xnn_operator, decltype(&xnn_delete_operator)>
             auto_convolution_op(convolution_op2, xnn_delete_operator);
 
-        xnnpack::Buffer<xnn_float16> output2(output.size(), UINT16_C(0xDEAD));
+        xnnpack::Buffer<xnn_float16> output2(output.size());
         size_t workspace_size = SIZE_MAX;
         size_t workspace_alignment = SIZE_MAX;
         ASSERT_EQ(xnn_status_success,

test/fully-connected-operator-tester.h

@@ -1786,7 +1786,7 @@ class FullyConnectedOperatorTester {
             batch_size(),
             /*threadpool=*/nullptr));
 
-        xnnpack::Buffer<xnn_float16> output2(output.size(), UINT16_C(0xDEAD));
+        xnnpack::Buffer<xnn_float16> output2(output.size());
         ASSERT_EQ(xnn_status_success,
           xnn_setup_fully_connected_nc_qd8_f16_qc8w(
             fully_connected_op2,

test/packw-microkernel-tester.h

@@ -343,10 +343,9 @@ class PackWMicrokernelTester {
         g() * (packed_n() * packed_k() + packed_n()));
     xnnpack::Buffer<xnn_float16> packed_w_ref(g() * (packed_n() * packed_k() + packed_n()));
 
-    const xnn_float16 pad_value = std::max(sr(), kr()) == 1 ? UINT16_C(0xDEAD) : 0;
-    std::iota(weights.begin(), weights.end(), UINT16_C(0x0001));
-    std::iota(bias.begin(), bias.end(), UINT16_C(0x8000));
-    std::fill(packed_w.begin(), packed_w.end(), UINT16_C(0xBEEF));
+    const xnn_float16 pad_value = xnn_float16_from_bits(std::max(sr(), kr()) == 1 ? UINT16_C(0xDEAD) : 0);
+    std::iota(weights.begin(), weights.end(), 1.0f);
+    std::iota(bias.begin(), bias.end(), 0.5f);
     std::fill(packed_w_ref.begin(), packed_w_ref.end(), pad_value);
 
     // Mandate zero-padding of weights to packed_k() in K dimension.
@@ -371,8 +370,8 @@ class PackWMicrokernelTester {
 
     // Call optimized micro-kernel.
     packw(g(), n(), k(), nr(), kr(), sr(),
-          reinterpret_cast<const uint16_t*>(weights.data()), 
-          reinterpret_cast<const uint16_t*>(bias_data), /*scale=*/nullptr, 
+          reinterpret_cast<const uint16_t*>(weights.data()),
+          reinterpret_cast<const uint16_t*>(bias_data), /*scale=*/nullptr,
           reinterpret_cast<uint16_t*>(packed_w.data()),
       /*extra_bytes=*/0, /*params=*/nullptr);