MIPS compiler flags: use -mfp32 or -mfp64 only if -mhard-float is used.

build/config/compiler/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/config.gni")
 if (current_cpu == "arm") {
   import("//build/config/arm.gni")
 }
 if (current_cpu == "mipsel" || current_cpu == "mips64el") {
   import("//build/config/mips.gni")
@@ skipping 277 matching lines @@
             ldflags += [
               "-mips32r6",
               "-Wl,-melf32ltsmip",
             ]
           }
         } else if (mips_arch_variant == "r2") {
           cflags += [
             "-mips32r2",
             "-Wa,-mips32r2",
           ]
-          if (mips_fpu_mode != "") {
+          if (mips_float_abi == "hard" && mips_fpu_mode != "") {
             cflags += [ "-m$mips_fpu_mode" ]
           }
         } else if (mips_arch_variant == "r1") {
           cflags += [
             "-mips32",
             "-Wa,-mips32",
           ]
         }
 
         if (mips_dsp_rev == 1) {
@@ skipping 785 matching lines @@
       cflags += [ "-gsplit-dwarf" ]
     }
   }
 }
 
 config("no_symbols") {
   if (!is_win) {
     cflags = [ "-g0" ]
   }
 }