Fix -fsanitize=integer warnings in v64_intrinsics_c.h

Change-Id: I8134c0ac4bd18478b266a0058e00bc6b1e6f8e9e

aom_dsp/simd/v64_intrinsics_c.h

diff --git a/aom_dsp/simd/v64_intrinsics_c.h b/aom_dsp/simd/v64_intrinsics_c.h
index a6e8e33..525070a 100644
--- a/aom_dsp/simd/v64_intrinsics_c.h
+++ b/aom_dsp/simd/v64_intrinsics_c.h
@@ -191,8 +191,8 @@
 
 SIMD_INLINE c_v64 c_v64_add_32(c_v64 a, c_v64 b) {
   c_v64 t;
-  t.u32[0] = a.u32[0] + b.u32[0];
-  t.u32[1] = a.u32[1] + b.u32[1];
+  t.u32[0] = (uint32_t)((uint64_t)a.u32[0] + b.u32[0]);
+  t.u32[1] = (uint32_t)((uint64_t)a.u32[1] + b.u32[1]);
   return t;
 }
 
@@ -207,9 +207,7 @@
   c_v64 t;
   int c;
   for (c = 0; c < 8; c++)
-    t.u8[c] = (int32_t)((uint32_t)a.u8[c] - (uint32_t)b.u8[c]) < 0
-                  ? 0
-                  : a.u8[c] - b.u8[c];
+    t.u8[c] = (int32_t)a.u8[c] - (int32_t)b.u8[c] < 0 ? 0 : a.u8[c] - b.u8[c];
   return t;
 }
 
@@ -244,8 +242,8 @@
 
 SIMD_INLINE c_v64 c_v64_sub_32(c_v64 a, c_v64 b) {
   c_v64 t;
-  t.u32[0] = a.u32[0] - b.u32[0];
-  t.u32[1] = a.u32[1] - b.u32[1];
+  t.u32[0] = (uint32_t)((int64_t)a.u32[0] - b.u32[0]);
+  t.u32[1] = (uint32_t)((int64_t)a.u32[1] - b.u32[1]);
   return t;
 }