aom_dsp/simd/v128_intrinsics_x86: fix int. sanitizer warnings

implicit conversion from type 'uint64_t' (aka 'unsigned long') of value
3436957635 (64-bit, unsigned) to type 'int' changed the value to
-858009661 (32-bit, signed)

BUG=aomedia:2357

Change-Id: I04ac7c9073343a69ebbb7c3f499624453c62d575
diff --git a/aom_dsp/simd/v128_intrinsics_x86.h b/aom_dsp/simd/v128_intrinsics_x86.h
index 6c7241f..fc3e5a2 100644
--- a/aom_dsp/simd/v128_intrinsics_x86.h
+++ b/aom_dsp/simd/v128_intrinsics_x86.h
@@ -89,7 +89,8 @@
 
 SIMD_INLINE v128 v128_dup_64(uint64_t x) {
   // _mm_set_pi64x and _mm_cvtsi64x_si64 missing in some compilers
-  return _mm_set_epi32(x >> 32, (uint32_t)x, x >> 32, (uint32_t)x);
+  return _mm_set_epi32((uint32_t)(x >> 32), (uint32_t)x, (uint32_t)(x >> 32),
+                       (uint32_t)x);
 }
 
 SIMD_INLINE v128 v128_add_8(v128 a, v128 b) { return _mm_add_epi8(a, b); }
@@ -538,7 +539,7 @@
 }
 
 SIMD_INLINE v128 v128_shr_u8(v128 a, unsigned int c) {
-  return _mm_and_si128(_mm_set1_epi8(0xff >> c),
+  return _mm_and_si128(_mm_set1_epi8((char)(0xff >> c)),
                        _mm_srl_epi16(a, _mm_cvtsi32_si128(c)));
 }