build: stop exporting V8's internals from the optimized runtime

set_target_properties takes key/value pairs, so the unquoted

    PROPERTIES LINK_FLAGS -Wl,--allow-multiple-definition -Wl,--exclude-libs=ALL -Wl,--gc-sections

set LINK_FLAGS to only -Wl,--allow-multiple-definition and then read
-Wl,--exclude-libs=ALL as a property name whose value was -Wl,--gc-sections,
which CMake silently discarded. libNativeScript.so was therefore exporting
72,662 dynamic symbols on arm64-v8a, 12.1 MiB of them .dynstr for names V8
never meant to publish.

Quote the flag list so all three apply, and hide the internals with a linker
version script rather than --exclude-libs=ALL: the latter would also hide
V8's public API, which plugins link against. exported-symbols.map keeps the
JNI entry points and v8::/cppgc:: public API global and everything else
local.

arm64-v8a, stripped: 47,433,360 -> 26,773,104 bytes; 72,662 -> 1,748
exported symbols, of which 8 v8::internal:: template instantiations whose
demangled name begins with a v8::Maybe<T> return type.

Author: edusperoni

test-app/runtime/CMakeLists.txt

@@ -174,7 +174,9 @@ set(NATIVES_BLOB_INCLUDE_DIRECTORIES ${PROJECT_SOURCE_DIR}/src/main/libs/${ANDRO
 if (OPTIMIZED_BUILD OR OPTIMIZED_WITH_INSPECTOR_BUILD)
     set_target_properties(
             NativeScript
-            PROPERTIES LINK_FLAGS -Wl,--allow-multiple-definition -Wl,--exclude-libs=ALL -Wl,--gc-sections
+            # The version script keeps V8's public API linkable for plugins while hiding
+            # the ~60k v8::internal:: symbols the static monolith would otherwise export.
+            PROPERTIES LINK_FLAGS "-Wl,--allow-multiple-definition -Wl,--gc-sections -Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/exported-symbols.map"
             INTERFACE_INCLUDE_DIRECTORIES NATIVES_BLOB_INCLUDE_DIRECTORIES
     )
 else ()

test-app/runtime/exported-symbols.map

@@ -0,0 +1,23 @@
+/*
+ * V8's public API lives directly under v8:: with an uppercase first letter
+ * (v8::Isolate, v8::Context, ...) while everything private is nested in
+ * v8::internal::. The split has to be made by case here: lld resolves a symbol
+ * matched by both a global: and a local: pattern in favour of global:, so the
+ * internals cannot be carved back out with a "local: v8::internal::*" entry.
+ *
+ * Patterns must stay unquoted -- a quoted string is matched literally, not as a
+ * wildcard.
+ */
+{
+  global:
+    Java_*;
+    JNI_OnLoad;
+    extern "C++" {
+      v8::[A-Z]*;
+      v8::api_internal::*;
+      v8::platform::*;
+      cppgc::[A-Z]*;
+    };
+  local:
+    *;
+};