Emscripten: Add wasm64 target (#927) * src/wasm32: Allow building with Emscripten with 64bit support MEMORY64 enables 64bit pointers so this commit updates the accessors for the libffi data structures accordingly. Each JS functions in ffi.c receives pointers as BigInt (i64) values and with casts them to Numer (i53) using bigintToI53Checked. While memory64 supports 64bit addressing, the maximum memory size is currently limited to 16GiB [1]. Therefore, we can assume that the passed pointers are within the Number's range. [1] https://webassembly.github.io/memory64/js-api/#limits Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> * Add wasm64 target to the build scripts This commit adds support for the wasm64 target via the configure script. Emscripten supports two modes of the -sMEMORY64 flag[1] so the script allows users specifying the value through a configuration variable. Additionally, "src/wasm32" directory has been renamed to the more generic "src/wasm" because it's now shared between both 32bit and 64bit builds. [1] https://emscripten.org/docs/tools_reference/settings_reference.html#memory64 Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> * GitHub Actions: Add wasm64 tests This commit adds a test matrix for wasm32, wasm64 and wasm64 with the -sMEMORY64=2 flag, using the latest version of Emscripten. -Wno-main is added to suppress the following warning in unwindtest.cc and unwindtest_ffi_call.cc. > FAIL: libffi.closures/unwindtest_ffi_call.cc -W -Wall -O2 (test for excess errors) > Excess errors: > ./libffi.closures/unwindtest_ffi_call.cc:20:5: warning: 'main' should not be 'extern "C"' [-Wmain] > 20 | int main (void) > | ^ > 1 warning generated. Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> * testsuite: Fix types of main function test_libffi.py calls each test's main function without arguments, but some tests define the main function with parameters. This signature mismatch causes a runtime error with the recent version of Emscripten. This commit resolves this issue by updating the function signatures to match the way they are called. Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> * README: Add document about WASM64 Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> --------- Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>