ANDROID: Makefile: LTO: gold-plugin func/data sections

LLVM's GOLD plugin changed default behavior in r336943 to create
separate function and data sections when linking. This caused a
significant boot time regression. r348389 made the behavior toggleable
with:

-plugin-opt=-function-sections
-plugin-opt=-data-sections

Add these to LD_FLAGS.

Bug: 119467548
Bug: 120503084
Change-Id: I6301f72f872d0c1725bc72cce3e250abf9bb3555
Signed-off-by: Nick Desaulniers <[email protected]>

Author: nickdesaulniers

Makefile

@@ -632,6 +632,8 @@ ifdef CONFIG_LTO_CLANG
 LDFINAL_vmlinux := $(LD)
 LD		:= $(LDGOLD)
 LDFLAGS		+= -plugin LLVMgold.so
+LDFLAGS		+= -plugin-opt=-function-sections
+LDFLAGS		+= -plugin-opt=-data-sections
 # use llvm-ar for building symbol tables from IR files, and llvm-dis instead
 # of objdump for processing symbol versions and exports
 LLVM_AR		:= llvm-ar