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/linker/error_delaying_output_stream.h b/compiler/linker/error_delaying_output_stream.h
index 99410e4..33e6b5a 100644
--- a/compiler/linker/error_delaying_output_stream.h
+++ b/compiler/linker/error_delaying_output_stream.h
@@ -22,6 +22,7 @@
 #include "base/logging.h"
 
 namespace art {
+namespace linker {
 
 // OutputStream wrapper that delays reporting an error until Flush().
 class ErrorDelayingOutputStream FINAL : public OutputStream {
@@ -96,6 +97,7 @@
   off_t output_offset_;  // Keep track of the current position in the stream.
 };
 
+}  // namespace linker
 }  // namespace art
 
 #endif  // ART_COMPILER_LINKER_ERROR_DELAYING_OUTPUT_STREAM_H_