MIPS: Fix unaligned read and write in wasm-debug.cc

Fix crashes in two tests cctest/test-wasm-interpreter-entry/TestArgumentPassing_AllTypes and
cctest/test-wasm-interpreter-entry/TestArgumentPassing_float_double related to accessing
double value through unaligned pointer. This issue is present on those architectures
that do not support unaligned access.

TEST=cctest/test-wasm-interpreter-entry/TestArgumentPassing_AllTypes,
     cctest/test-wasm-interpreter-entry/TestArgumentPassing_float_double
BUG=

Review-Url: https://codereview.chromium.org/2705253003
Cr-Commit-Position: refs/heads/master@{#43387}

src/wasm/wasm-debug.cc

@@ -89,7 +89,7 @@ class InterpreterHandle {
 #define CASE_ARG_TYPE(type, ctype)                                  \
   case type:                                                        \
     DCHECK_EQ(param_size, sizeof(ctype));                           \
-    wasm_args[i] = WasmVal(*reinterpret_cast<ctype*>(arg_buf_ptr)); \
+    wasm_args[i] = WasmVal(ReadUnalignedValue<ctype>(arg_buf_ptr)); \
     break;
       switch (sig->GetParam(i)) {
         CASE_ARG_TYPE(kWasmI32, uint32_t)
@@ -143,7 +143,7 @@ class InterpreterHandle {
 #define CASE_RET_TYPE(type, ctype)                                       \
   case type:                                                             \
     DCHECK_EQ(1 << ElementSizeLog2Of(sig->GetReturn(0)), sizeof(ctype)); \
-    *reinterpret_cast<ctype*>(arg_buffer) = ret_val.to<ctype>();         \
+    WriteUnalignedValue<ctype>(arg_buffer, ret_val.to<ctype>());         \
     break;
       switch (sig->GetReturn(0)) {
         CASE_RET_TYPE(kWasmI32, uint32_t)