Revert "Disable ABI on the master branch. (#5641)" (#5649)

This reverts commit a0a3aba.

infra/ansible/config/env.yaml

@@ -33,7 +33,6 @@ build_env:
     BAZEL_REMOTE_CACHE: 1
     SILO_NAME: "cache-silo-{{ arch }}-{{ accelerator }}-{{ clang_version }}"
     DISABLE_XRT: "{{ disable_xrt }}"
-    CXX_ABI: 0
 
   amd64:
     ARCH: amd64

infra/ansible/roles/build_srcs/tasks/main.yaml

@@ -17,6 +17,18 @@
     name: "{{ pytorch_wheels.files | map(attribute='path') }}"
     state: "forcereinstall"
 
+- name: Check if build_torch_xla_libs.sh script exists
+  stat:
+    path: "{{ (src_root, 'pytorch/xla/build_torch_xla_libs.sh') | path_join }}"
+  register: build_torch_xla_libs_result
+
+- name: Build XLA computation client library
+  ansible.builtin.command:
+    cmd: bash build_torch_xla_libs.sh -O -D_GLIBCXX_USE_CXX11_ABI=1
+    chdir: "{{ (src_root, 'pytorch/xla') | path_join }}"
+  environment: "{{ env_vars }}"
+  when: build_torch_xla_libs_result.stat.exists
+
 - name: Build PyTorch/XLA
   ansible.builtin.command:
     cmd: python setup.py bdist_wheel