Bug 1192277 - remove check for LLVM PR 8927; r=glandium

The PR was fixed in early 2011.  clang 3.3, the oldest version of clang
that we build with, was released in mid-2013.  It's safe to say that all
versions of clang now have this fix, and we can delete the check.

aclocal.m4

@@ -19,7 +19,6 @@ builtin(include, build/autoconf/mozprog.m4)dnl
 builtin(include, build/autoconf/mozheader.m4)dnl
 builtin(include, build/autoconf/mozcommonheader.m4)dnl
 builtin(include, build/autoconf/lto.m4)dnl
-builtin(include, build/autoconf/llvm-pr8927.m4)dnl
 builtin(include, build/autoconf/frameptr.m4)dnl
 builtin(include, build/autoconf/compiler-opts.m4)dnl
 builtin(include, build/autoconf/expandlibs.m4)dnl

build/autoconf/llvm-pr8927.m4

-dnl This Source Code Form is subject to the terms of the Mozilla Public
-dnl License, v. 2.0. If a copy of the MPL was not distributed with this
-dnl file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-dnl Check if the compiler suffers from http://llvm.org/pr8927. If so, ask the
-dnl user to upgrade.
-
-AC_DEFUN([MOZ_LLVM_PR8927],
-[
-AC_MSG_CHECKING(for llvm pr8927)
-ac_have_llvm_pr8927="no"
-AC_LANG_SAVE
-AC_LANG_C
-
-_SAVE_CFLAGS=$CFLAGS
-CFLAGS="-O2"
-AC_TRY_RUN([
-struct foobar {
-  int x;
-};
-static const struct foobar* foo() {
-  static const struct foobar d = { 0 };
-  return &d;
-}
-static const struct foobar* bar() {
-  static const struct foobar d = { 0 };
-  return &d;
-}
-__attribute__((noinline)) int zed(const struct foobar *a,
-                                  const struct foobar *b) {
-  return a == b;
-}
-int main() {
-  return zed(foo(), bar());
-}
-], true,
-   ac_have_llvm_pr8927="yes",
-   true)
-CFLAGS="$_SAVE_CFLAGS"
-
-AC_LANG_RESTORE
-
-if test "$ac_have_llvm_pr8927" = "yes"; then
-   AC_MSG_RESULT(yes)
-   echo This compiler would miscompile firefox, please upgrade.
-   echo see http://developer.mozilla.org/en-US/docs/Developer_Guide/Build_Instructions/Mac_OS_X_Prerequisites
-   echo for more information.
-   exit 1
-else
-   AC_MSG_RESULT(no)
-fi
-])

configure.in

@@ -2643,8 +2643,6 @@ esac
 AC_SUBST(WRAP_SYSTEM_INCLUDES)
 AC_SUBST(VISIBILITY_FLAGS)
 
-MOZ_LLVM_PR8927
-
 dnl Checks for header files.
 dnl ========================================================
 AC_HEADER_DIRENT

js/src/aclocal.m4

@@ -18,7 +18,6 @@ builtin(include, ../../build/autoconf/mozprog.m4)dnl
 builtin(include, ../../build/autoconf/mozheader.m4)dnl
 builtin(include, ../../build/autoconf/mozcommonheader.m4)dnl
 builtin(include, ../../build/autoconf/lto.m4)dnl
-builtin(include, ../../build/autoconf/llvm-pr8927.m4)dnl
 builtin(include, ../../build/autoconf/frameptr.m4)dnl
 builtin(include, ../../build/autoconf/compiler-opts.m4)dnl
 builtin(include, ../../build/autoconf/expandlibs.m4)dnl