Modified MIPS MSA default argument settings

1. Disabled msa by default
2. Removed compiler flags

R=dpranke@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2326453002
Cr-Commit-Position: refs/heads/master@{#419419}

build/config/compiler/BUILD.gn

@@ -576,8 +576,6 @@ config("compiler_cpu_abi") {
           cflags += [
             "-mmsa",
             "-mfp64",
-            "-msched-weight",
-            "-mload-store-pairs",
           ]
         }
       } else if (mips_arch_variant == "r2") {
@@ -660,8 +658,6 @@ config("compiler_cpu_abi") {
           cflags += [
             "-mmsa",
             "-mfp64",
-            "-msched-weight",
-            "-mload-store-pairs",
           ]
         }
       } else if (mips_arch_variant == "r2") {

build/config/mips.gni

@@ -23,7 +23,7 @@ if (current_cpu == "mipsel" || v8_current_cpu == "mipsel") {
     mips_dsp_rev = 0
 
     # MIPS SIMD Arch compilation flag.
-    mips_use_msa = true
+    mips_use_msa = false
 
     # MIPS floating-point ABI. Possible values are:
     #   "hard": sets the GCC -mhard-float option.
@@ -50,6 +50,9 @@ if (current_cpu == "mipsel" || v8_current_cpu == "mipsel") {
   } else {
     declare_args() {
       mips_arch_variant = "r2"
+
+      # MIPS SIMD Arch compilation flag.
+      mips_use_msa = false
     }
   }
 }