subsys/cpp: Also run C++ tests with picolibc when possible

When the toolchain has picolibc support, run
samples/subsys/cpp/cpp_synchronization and tests/subsys/cpp/libcxx tests
using it.

Signed-off-by: Keith Packard <keithp@keithp.com>

samples/cpp/cpp_synchronization/sample.yaml

@@ -13,3 +13,18 @@ tests:
         - "Create semaphore (.*)"
         - "main: Hello World!"
         - "coop_thread_entry: Hello World!"
+  sample.cpp.synchronization.picolibc:
+    filter: CONFIG_PICOLIBC_SUPPORTED
+    extra_configs:
+      - CONFIG_PICOLIBC=y
+    tags: cpp
+    toolchain_exclude: issm xcc
+    integration_platforms:
+      - qemu_x86
+    harness: console
+    harness_config:
+      type: multi_line
+      regex:
+        - "Create semaphore (.*)"
+        - "main: Hello World!"
+        - "coop_thread_entry: Hello World!"

tests/lib/cpp/libcxx/testcase.yaml

@@ -23,6 +23,17 @@ tests:
       - CONFIG_GLIBCXX_LIBCPP=y
     integration_platforms:
       - mps2_an385
+  cpp.libcxx.glibcxx.picolibc:
+    filter: TOOLCHAIN_HAS_PICOLIBC == 1
+    toolchain_exclude: xcc
+    tags: cpp
+    timeout: 60
+    extra_configs:
+      - CONFIG_PICOLIBC=y
+      - CONFIG_GLIBCXX_LIBCPP=y
+      - CONFIG_CPP_EXCEPTIONS=y
+    integration_platforms:
+      - mps2_an385
   cpp.libcxx.arcmwdtlib:
     toolchain_allow: arcmwdt
     min_flash: 54