gcc-4.9: move binaries to find build breakages

As per:
https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/+/master/GCC_4_9_DEPRECATION.md
We're about to remove gcc-4.9; move the binaries to see if we can spot
any build breakages in pre or post submit testing.

Build cops may revert this change if necessary.

Please report any unexpected build breakages to: android-llvm@googlegroups.com

Bug: 147240075
Change-Id: I6f42e797cd43c3fefd594a37bc818972b3304e70
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
7 files changed