Revert "Remove libcpp_is_static"

This reverts commit f002a96e9b788fe71fd1c773a4bc891940c409d8.

Reason for revert: Dirk bisected the chromeos asan failures and it appears this is the culprit. The output from the failing bots isn't particularly helpful as it doesn't have symbols. Here's a recent failure: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/28402

BUG=867826

Original change's description:
> Remove libcpp_is_static
> 
> This change makes libc++ a shared_library iff is_component_build=true, just like
> all other components.  This has the advantage that the RPATH doesn't need to be
> set in sanitizer (non-component) builds just so binaries can find libc++.so.
> This CL also changes RPATH to be set iff is_component_build=true.
> 
> Needs buildtools CL:
> https://chromium-review.googlesource.com/c/chromium/buildtools/+/1142370
> 
> TBR=dpranke,jochen
> R=​thakis
> BUG=850682
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_ubsan_rel_ng;luci.chromium.try:linux_chromium_asan_rel_ng;luci.chromium.try:linux_chromium_tsan_rel_ng
> 
> Change-Id: I96e74da6d907659b939a0f229693bbd2a6d9140a
> Reviewed-on: https://chromium-review.googlesource.com/1119098
> Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
> Reviewed-by: Peter Collingbourne <pcc@chromium.org>
> Reviewed-by: Nico Weber <thakis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#578085}

TBR=thakis@chromium.org,pcc@chromium.org,thomasanderson@chromium.org

Change-Id: Ieec9ae83b7c12004521358cf71eb2d09fdfc7a09
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 850682
Cq-Include-Trybots: luci.chromium.try:linux_chromium_msan_rel_ng;master.tryserver.chromium.linux:linux_chromium_ubsan_rel_ng;luci.chromium.try:linux_chromium_asan_rel_ng;luci.chromium.try:linux_chromium_tsan_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1151917
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578435}
10 files changed