Switch to using ELF-64 for 64-bit architectures.

Bug: 21297086
Change-Id: I4914e097ceffa58ddbe567d23ab563b0d9db1f66
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 47288b5..7cb7489 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -74,8 +74,8 @@
 
 static constexpr bool kTimeCompileMethod = !kIsDebugBuild;
 
-// Whether to produce 64-bit ELF files for 64-bit targets. Leave this off for now.
-static constexpr bool kProduce64BitELFFiles = false;
+// Whether to produce 64-bit ELF files for 64-bit targets.
+static constexpr bool kProduce64BitELFFiles = true;
 
 // Whether classes-to-compile and methods-to-compile are only applied to the boot image, or, when
 // given, too all compilations.