still force libc++ to link as shared for now

Summary:
We can't force libc++ to be statically linked, even in opt mode due to the present of DSOs, which are widely used in Python environments.
Without this patch, cinderx wouldn't work due to its duplicate static and dynamic linkage to libc++.

While static linkage to libc++ remains possible in the absence of DSOs, let's force shared for now until we found a solution.

Reviewed By: skrueger

Differential Revision: D87374284

fbshipit-source-id: f8053c02c3cf3ba0d71247075103ff39b483c6cd

Author: yuxuanchen1997

folly/debugging/exception_tracer/BUCK

@@ -189,15 +189,6 @@ FBCODE_STATIC_LIBSTDCXX_SELECTOR = selects.and_(
     ),
 )
 
-FBCODE_STATIC_LIBCXX_SELECTOR = selects.and_(
-    selects.cond("ovr_config//runtime/constraints:fbcode"),
-    selects.cond("ovr_config//cpp:libc++"),
-    selects.or_(
-        selects.cond("ovr_config//build_mode/constraints:static"),
-        selects.cond("ovr_config//build_mode/constraints:static_pic"),
-    ),
-)
-
 FOLLY_SHOULD_INSTALL_STATIC_CXA_FUNCTIONS_WRAPPERS = selects.or_(
     selects.cond("fbsource//xplat/toolchains/android/ndk:cxx-static-runtime-type"),
     FBCODE_STATIC_LIBSTDCXX_SELECTOR,
@@ -206,7 +197,6 @@ FOLLY_SHOULD_INSTALL_STATIC_CXA_FUNCTIONS_WRAPPERS = selects.or_(
 FOLLY_SHOULD_INSTALL_STD_RETHROW_EXCEPTION_WRAPPER = selects.or_(
     selects.cond("fbsource//xplat/toolchains/android/ndk:cxx-static-runtime-type"),
     FBCODE_STATIC_LIBSTDCXX_SELECTOR,
-    FBCODE_STATIC_LIBCXX_SELECTOR,
 )
 
 EXCEPTION_TRACER_LIB_COMPILER_FLAGS = selects.if_(
@@ -358,17 +348,8 @@ LIBSTDCXX_BUCKIFIED_SELECTOR = selects.and_(
     selects.cond("ovr_config//third-party/libgcc:11.x"),
 )
 
-LIBCXX_STATIC_SELECTOR = selects.and_(
-    selects.cond("ovr_config//cpp:libc++"),
-    selects.or_(
-        selects.cond("ovr_config//build_mode/constraints:static"),
-        selects.cond("ovr_config//build_mode/constraints:static_pic"),
-    ),
-)
-
 STATIC_CXX_STDLIB_SELECTOR = selects.or_(
     LIBSTDCXX_BUCKIFIED_SELECTOR,
-    LIBCXX_STATIC_SELECTOR,
 )
 
 fbcode_target(