Refactor linker files from compiler/ to dex2oat/.

This shifts some code from the libart-compiler.so to dex2oat
and reduces memory needed for JIT. We also avoid loading the
libart-dexlayout.so for JIT but the memory savings are
minimal (one shared clean page, two shared dirty pages and
some per-app kernel mmap data) as the code has never been
needed in memory by JIT.

aosp_angler-userdebug file sizes (stripped):
  lib64/libart-compiler.so: 2989112 -> 2671888 (-310KiB)
  lib/libart-compiler.so: 2160816 -> 1939276 (-216KiB)
  bin/dex2oat: 141868 -> 368808 (+222KiB)
LOAD/executable elf mapping sizes:
  lib64/libart-compiler.so: 2866308 -> 2555500 (-304KiB)
  lib/libart-compiler.so: 2050960 -> 1834836 (-211KiB)
  bin/dex2oat: 129316 -> 345916 (+212KiB)

Test: m test-art-host-gtest
Test: testrunner.py --host
Test: cd art/; mma; cd -
Change-Id: If62f02847a6cbb208eaf7e1f3e91af4663fa4a5f
diff --git a/compiler/debug/elf_gnu_debugdata_writer.h b/compiler/debug/elf_gnu_debugdata_writer.h
index fb63d62..1cdf6b0 100644
--- a/compiler/debug/elf_gnu_debugdata_writer.h
+++ b/compiler/debug/elf_gnu_debugdata_writer.h
@@ -20,7 +20,7 @@
 #include <vector>
 
 #include "arch/instruction_set.h"
-#include "elf_builder.h"
+#include "linker/elf_builder.h"
 #include "linker/vector_output_stream.h"
 
 // liblzma.
@@ -85,8 +85,9 @@
     const ArrayRef<const MethodDebugInfo>& method_infos) {
   std::vector<uint8_t> buffer;
   buffer.reserve(KB);
-  VectorOutputStream out("Mini-debug-info ELF file", &buffer);
-  std::unique_ptr<ElfBuilder<ElfTypes>> builder(new ElfBuilder<ElfTypes>(isa, features, &out));
+  linker::VectorOutputStream out("Mini-debug-info ELF file", &buffer);
+  std::unique_ptr<linker::ElfBuilder<ElfTypes>> builder(
+      new linker::ElfBuilder<ElfTypes>(isa, features, &out));
   builder->Start();
   // Mirror .rodata and .text as NOBITS sections.
   // It is needed to detected relocations after compression.