Merge pull request #6224 from dgquintas/gcc6

Casting fixes for gcc 6.0

src/core/ext/transport/chttp2/transport/bin_encoder.c

@@ -194,9 +194,13 @@ gpr_slice grpc_chttp2_base64_encode_and_huffman_compress_impl(gpr_slice input) {
 
   /* encode full triplets */
   for (i = 0; i < input_triplets; i++) {
-    enc_add2(&out, in[0] >> 2, (uint8_t)((in[0] & 0x3) << 4) | (in[1] >> 4));
-    enc_add2(&out, (uint8_t)((in[1] & 0xf) << 2) | (in[2] >> 6),
-             (uint8_t)(in[2] & 0x3f));
+    const uint8_t low_to_high = (uint8_t)((in[0] & 0x3) << 4);
+    const uint8_t high_to_low = in[1] >> 4;
+    enc_add2(&out, in[0] >> 2, low_to_high | high_to_low);
+
+    const uint8_t a = (uint8_t)((in[1] & 0xf) << 2);
+    const uint8_t b = (in[2] >> 6);
+    enc_add2(&out, a | b, in[2] & 0x3f);
     in += 3;
   }
 
@@ -208,12 +212,14 @@ gpr_slice grpc_chttp2_base64_encode_and_huffman_compress_impl(gpr_slice input) {
       enc_add2(&out, in[0] >> 2, (uint8_t)((in[0] & 0x3) << 4));
       in += 1;
       break;
-    case 2:
-      enc_add2(&out, in[0] >> 2,
-               (uint8_t)((in[0] & 0x3) << 4) | (uint8_t)(in[1] >> 4));
+    case 2: {
+      const uint8_t low_to_high = (uint8_t)((in[0] & 0x3) << 4);
+      const uint8_t high_to_low = in[1] >> 4;
+      enc_add2(&out, in[0] >> 2, low_to_high | high_to_low);
       enc_add1(&out, (uint8_t)((in[1] & 0xf) << 2));
       in += 2;
       break;
+    }
   }
 
   if (out.temp_length) {