[MIPS] Unite mipsel and mips64el 4.9 gcc toolchains

Use 4.9 mips64el toolchain for both 64- and 32-bit builds.
Tell ld when 32-bit links are required.
Override 4.9's changed defaults for mips floating point
register use, to get same assembler rules as 4.8 and earlier.

Also: drop unused  soft-fp build targets, cleanout redundant
compiler options, and remove extraneous Android.mk file.

Change-Id: I86f1075266349edb2b08a7709b9f5472d8cfda32
diff --git a/core/combo/TARGET_linux-mips.mk b/core/combo/TARGET_linux-mips.mk
index d702cc5..cb1e19d 100644
--- a/core/combo/TARGET_linux-mips.mk
+++ b/core/combo/TARGET_linux-mips.mk
@@ -38,7 +38,7 @@
 $(combo_2nd_arch_prefix)TARGET_NDK_GCC_VERSION := 4.8
 
 ifeq ($(strip $(TARGET_GCC_VERSION_EXP)),)
-$(combo_2nd_arch_prefix)TARGET_GCC_VERSION := 4.8
+$(combo_2nd_arch_prefix)TARGET_GCC_VERSION := 4.9
 else
 $(combo_2nd_arch_prefix)TARGET_GCC_VERSION := $(TARGET_GCC_VERSION_EXP)
 endif
@@ -52,8 +52,8 @@
 
 # You can set TARGET_TOOLS_PREFIX to get gcc from somewhere else
 ifeq ($(strip $($(combo_2nd_arch_prefix)TARGET_TOOLS_PREFIX)),)
-$(combo_2nd_arch_prefix)TARGET_TOOLCHAIN_ROOT := prebuilts/gcc/$(HOST_PREBUILT_TAG)/mips/mipsel-linux-android-$($(combo_2nd_arch_prefix)TARGET_GCC_VERSION)
-$(combo_2nd_arch_prefix)TARGET_TOOLS_PREFIX := $($(combo_2nd_arch_prefix)TARGET_TOOLCHAIN_ROOT)/bin/mipsel-linux-android-
+$(combo_2nd_arch_prefix)TARGET_TOOLCHAIN_ROOT := prebuilts/gcc/$(HOST_PREBUILT_TAG)/mips/mips64el-linux-android-$($(combo_2nd_arch_prefix)TARGET_GCC_VERSION)
+$(combo_2nd_arch_prefix)TARGET_TOOLS_PREFIX := $($(combo_2nd_arch_prefix)TARGET_TOOLCHAIN_ROOT)/bin/mips64el-linux-android-
 endif
 
 $(combo_2nd_arch_prefix)TARGET_CC := $($(combo_2nd_arch_prefix)TARGET_TOOLS_PREFIX)gcc$(HOST_EXECUTABLE_SUFFIX)
@@ -96,24 +96,6 @@
 			-include $(android_config_h) \
 			-I $(dir $(android_config_h))
 
-# This warning causes dalvik not to build with gcc 4.6+ and -Werror.
-# We cannot turn it off blindly since the option is not available
-# in gcc-4.4.x.
-ifneq ($(filter 4.6 4.6.% 4.7 4.7.% 4.8, $($(combo_2nd_arch_prefix)TARGET_GCC_VERSION)),)
-$(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += -Wno-unused-but-set-variable \
-                        -fno-strict-volatile-bitfields
-endif
-
-# This is to avoid the dreaded warning compiler message:
-#   note: the mangling of 'va_list' has changed in GCC 4.4
-#
-# The fact that the mangling changed does not affect the NDK ABI
-# very fortunately (since none of the exposed APIs used va_list
-# in their exported C++ functions). Also, GCC 4.5 has already
-# removed the warning from the compiler.
-#
-$(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += -Wno-psabi
-
 ifneq ($(ARCH_MIPS_PAGE_SHIFT),)
 $(combo_2nd_arch_prefix)TARGET_GLOBAL_CFLAGS += -DPAGE_SHIFT=$(ARCH_MIPS_PAGE_SHIFT)
 endif