Enable clang for x86_64 after fp128 fix in clang-2577113.

Upstream LLVM fix was included in prebuilt clang-2577113.

BUG: 21899249
Change-Id: Ief3f3e28650c0bbf8749a5e5d26f45c39e15ed62

libc/Android.mk

@@ -610,12 +610,6 @@ libc_common_cflags := \
 
 use_clang := $(USE_CLANG_PLATFORM_BUILD)
 
-# Clang/llvm has incompatible long double (fp128) for x86_64.
-# https://llvm.org/bugs/show_bug.cgi?id=23897
-ifeq ($(TARGET_ARCH),x86_64)
-  use_clang := false
-endif
-
 # b/25291096, Clang/llvm compiled libc.so for mips/mips64 failed to boot.
 ifeq ($(TARGET_ARCH),$(filter $(TARGET_ARCH),mips mips64))
   use_clang := false

libm/Android.mk

@@ -3,12 +3,6 @@ LOCAL_PATH:= $(call my-dir)
 
 bionic_coverage := false
 
-# Clang/llvm has incompatible long double (fp128) for x86_64.
-# https://llvm.org/bugs/show_bug.cgi?id=23897
-ifeq ($(TARGET_ARCH),x86_64)
-libm_clang := false
-endif
-
 # -----------------------------------------------------------------------------
 # libm.a
 # -----------------------------------------------------------------------------

tests/Android.mk

@@ -137,13 +137,6 @@ libBionicStandardTests_static_libraries := \
 libBionicStandardTests_ldlibs_host := \
     -lrt \
 
-# Clang/llvm has incompatible long double (fp128) for x86_64.
-# https://llvm.org/bugs/show_bug.cgi?id=23897
-# This affects most of math_test.cpp.
-ifeq ($(TARGET_ARCH),$(filter $(TARGET_ARCH),x86_64))
-libBionicStandardTests_clang_target := false
-endif
-
 module := libBionicStandardTests
 module_tag := optional
 build_type := target