Reinstate armv4t and armv5te compiler_rt and libcxx tests

Pull request #109628 automatically turned on frame pointers for leaf functions
in Clang when frame pointers are enabled. This triggered a latent bug in
picolibc for armv4t and armv5te, which consequentially broke our tests for them.

There is currently a pull request that fixes this
bug (picolibc/picolibc#897), but we don't have to wait
for this to merge to reinstate the tests, because we recently changed the
behaviour of Clang to by default omit frame pointers altogether
(llvm/llvm-project#117140), and that is how picolibc is
built now. In general the advice is that you shouldn't build AArch32 targets
with frame pointers enabled for various reasons.

arm-multilib/json/variants/armv4t.json

@@ -21,9 +21,9 @@
         "picolibc": {
             "PICOLIBC_BUILD_TYPE": "minsize",
             "ENABLE_CXX_LIBS": "ON",
-            "ENABLE_LIBC_TESTS": "OFF",
-            "ENABLE_COMPILER_RT_TESTS": "OFF",
-            "ENABLE_LIBCXX_TESTS": "OFF"
+            "ENABLE_LIBC_TESTS": "ON",
+            "ENABLE_COMPILER_RT_TESTS": "ON",
+            "ENABLE_LIBCXX_TESTS": "ON"
         },
         "newlib": {
             "ENABLE_CXX_LIBS": "ON",
@@ -38,4 +38,4 @@
             "ENABLE_LIBCXX_TESTS": "OFF"
         }
     }
-}
+}

arm-multilib/json/variants/armv5te.json

@@ -21,9 +21,9 @@
         "picolibc": {
             "PICOLIBC_BUILD_TYPE": "minsize",
             "ENABLE_CXX_LIBS": "ON",
-            "ENABLE_LIBC_TESTS": "OFF",
-            "ENABLE_COMPILER_RT_TESTS": "OFF",
-            "ENABLE_LIBCXX_TESTS": "OFF"
+            "ENABLE_LIBC_TESTS": "ON",
+            "ENABLE_COMPILER_RT_TESTS": "ON",
+            "ENABLE_LIBCXX_TESTS": "ON"
         },
         "newlib": {
             "ENABLE_CXX_LIBS": "ON",
@@ -38,4 +38,4 @@
             "ENABLE_LIBCXX_TESTS": "OFF"
         }
     }
-}
+}