Bad interaction of -fuse-ld=lld and statically linked libc++

Our platform is Ubuntu 22.04. We import the OpenUSD package as a prebuilt tarball (built with clang) into bazel targets for use within our code-base. A small test program that exercises some basic functionality in OpenUSD crashes during static initialization with an error like this:

```
a_rao@a-rao-ubuntu:$ bazel test //examples/hello_world:test_usd
test_usd: mbrtowc.c:104: __mbrtowc: Assertion `__mbsinit (data.__statep)' failed.
Aborted (core dumped)
```

After much debugging, the culprit appears to be `-fuse-ld=lld`, which also apparently causes` libc++.a`,` libc++abi.a` and `libunwind.a` to be statically linked. Either of these by themselves is fine, but together, they cause the crash.

Also: using `clang++` instead of `clang` also fixes the problem (without changing anything else).

The workaround is to add linkopts to the build rule for the test program:

```
cc.test(
name = "test_usd",
srcs = ["test_usd.cpp"],
args = ["/tmp/hello_world.usda"],
copts = [
"-Wno-#pragma-messages",
"-Wno-deprecated-volatile",
],
linkopts = [
"-fuse-ld=ld",
"-lc++",
"-lc++abi",
"-lunwind",
],
deps = [
"//external/OpenUSD:usd_tf",
"//external/OpenUSD:usd_usd",
"//external/OpenUSD:usd_usdGeom",
],
)
```

Reproduce the failure with bazel test //examples/hello_world:test_usd using the cc.test target and the OpenUSD dependencies described in the issue. Compare linking through clang versus clang++ and the -fuse-ld=lld workaround, then trace the toolchain's handling of libc++.a, libc++abi.a, and libunwind.a. Done means the test no longer crashes during static initialization without the workaround.

Written by the indexing model from the issue text.