MIPS: Fix unaligned memory access in hash calculation

During hash calculation, an array type was reinterpreted
from uint16_[] to uint32_t[]. Uint32 arrays have stricter
alignment requirements and these causes failures of several
tests from the debugger suite.

TEST=debugger/debug/debug-eval-scope

Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I463c7aeb56a1010ddfb0c34f8404f05b75e6c466
Reviewed-on: https://chromium-review.googlesource.com/926341
Commit-Queue: Ivica Bogosavljevic <ivica.bogosavljevic@mips.com>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51398}

src/inspector/DEPS

@@ -7,6 +7,7 @@ include_rules = [
   "+src/base/platform/platform.h",
   "+src/conversions.h",
   "+src/flags.h",
+  "+src/utils.h",
   "+src/unicode-cache.h",
   "+src/inspector",
   "+src/tracing",

src/inspector/v8-debugger-script.cc

@@ -7,6 +7,7 @@
 #include "src/inspector/inspected-context.h"
 #include "src/inspector/string-util.h"
 #include "src/inspector/wasm-translation.h"
+#include "src/utils.h"
 
 namespace v8_inspector {
 
@@ -45,10 +46,11 @@ String16 calculateHash(const String16& str) {
   size_t sizeInBytes = sizeof(UChar) * str.length();
   data = reinterpret_cast<const uint32_t*>(str.characters16());
   for (size_t i = 0; i < sizeInBytes / 4; ++i) {
+    uint32_t d = v8::internal::ReadUnalignedUInt32(data + i);
 #if V8_TARGET_LITTLE_ENDIAN
-    uint32_t v = data[i];
+    uint32_t v = d;
 #else
-    uint32_t v = (data[i] << 16) | (data[i] >> 16);
+    uint32_t v = (d << 16) | (d >> 16);
 #endif
     uint64_t xi = v * randomOdd[current] & 0x7FFFFFFF;
     hashes[current] = (hashes[current] + zi[current] * xi) % prime[current];
@@ -57,15 +59,16 @@ String16 calculateHash(const String16& str) {
   }
   if (sizeInBytes % 4) {
     uint32_t v = 0;
+    const uint8_t* data_8b = reinterpret_cast<const uint8_t*>(data);
     for (size_t i = sizeInBytes - sizeInBytes % 4; i < sizeInBytes; ++i) {
       v <<= 8;
 #if V8_TARGET_LITTLE_ENDIAN
-      v |= reinterpret_cast<const uint8_t*>(data)[i];
+      v |= data_8b[i];
 #else
       if (i % 2) {
-        v |= reinterpret_cast<const uint8_t*>(data)[i - 1];
+        v |= data_8b[i - 1];
       } else {
-        v |= reinterpret_cast<const uint8_t*>(data)[i + 1];
+        v |= data_8b[i + 1];
       }
 #endif
     }