X87: [test] disable number-tostring test case for x87.

  The reason:
  The CL #41255 (https://codereview.chromium.org/2520363002 ) reimplemnt the Number.prototype.toString and the added number-tostring test cases failed at x87.

  Similar to many previos fixing CLs, i.e.: CL #37371 (https://codereview.chromium.org/2111493002 ), the root reason is:
  The Gcc compiler and it's dependent C++ libraris on linux platform use x87 in extended 80-bit double precision by default.
  So the reimplemented DoubleToRadixCString() will generate extended 80-bit double precision result which isn't the expected standard 64-bit double precision
  value.

  Although modifying DoubleToRadixCString() function to manually do the 80-bit <--> 64-bit conversion for each double/float computation step can fix this issue,
  but it wll drop the DoubleToRadixCString() function's performance of other architectures.

  This CL put the failed number-tostring test cases into number-tostring-big-integer.js and disables it for x87.

BUG=

Review-Url: https://codereview.chromium.org/2532073002
Cr-Commit-Position: refs/heads/master@{#41322}

test/mjsunit/mjsunit.status

@@ -495,6 +495,12 @@
   'math-floor-of-div-minus-zero': [SKIP],
 }],  # 'arch == mips64el or arch == mips64'
 
+['arch == x87', {
+   # The result produced by Gcc on linux platform is extended 80-bit double
+   # precision and not the expected standard 64-bit double precision.
+   'number-tostring-big-integer': [SKIP],
+}],  # 'arch == x87'
+
 ##############################################################################
 ['system == windows', {
   # TODO(mstarzinger): Too slow with turbo fan.

test/mjsunit/number-tostring-big-integer.js

+// Copyright 2008 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// This file is a subset of the number-tostring mjsunit tests which test
+// precision for base conversion for large integers.
+
+// ----------------------------------------------------------------------
+// toString
+assertEquals("314404114120101444444424000000000000000",
+             (1.2345e+27).toString(5));

test/mjsunit/number-tostring.js

@@ -151,9 +151,6 @@ assertEquals("10000", (81).toString(3));
 assertEquals("10000.01", (81 + 1/9).toString(3));
 assertEquals("0.0212010212010212010212010212010212", (2/7).toString(3));
 
-assertEquals("314404114120101444444424000000000000000",
-             (1.2345e+27).toString(5));
-
 // ----------------------------------------------------------------------
 // toFixed
 assertEquals("NaN", (NaN).toFixed(2));