Fix WASM build issues, improve test coverage and improve cmake files

* Ensure compiler.usethread=0 is set before compilation in single-threaded WASM builds
* Explicitly enable exceptions for the single-threaded WASM module
* Test the single-threaded module in addition to the multi-threaded module in internal and external CI
* Consolidate wasm/tests/CMakeLists.txt into wasm/CMakeLists.txt, fixing the single-threaded benchmark test build which was missing shared linker flags

PiperOrigin-RevId: 901149728
Change-Id: If4946e29e5116610782d218906cf3f5940c1cdd0

wasm/tests/CMakeLists.txt

@@ -1,63 +0,0 @@
-# Copyright 2025 DeepMind Technologies Limited
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/wasm/dist")
-
-set(CMAKE_INSTALL_PREFIX ${PROJECT_SOURCE_DIR}/wasm)
-
-include_directories(${PROJECT_SOURCE_DIR}/include)
-include_directories(${PROJECT_SOURCE_DIR}/src)
-include_directories(${PROJECT_SOURCE_DIR})
-
-link_directories(${CMAKE_BINARY_DIR}/lib)
-
-file(GLOB MUJOCO_WASM_FILES
-    "benchmark_test.cc"
-    "../unpack.cc"
-)
-
-if(NOT MUJOCO_WASM_FILES)
-    message(FATAL_ERROR "No source files found")
-endif()
-
-# Set Emscripten linker flags
-set(EMCC_LINKER_FLAGS
-    "--bind"
-    "-pthread"
-    "-s PTHREAD_POOL_SIZE=navigator.hardwareConcurrency"
-    "-s ASSERTIONS=1"
-    "-s ALLOW_MEMORY_GROWTH=1"
-    "-s EXPORT_ES6=1"
-    "-s MODULARIZE=1"
-    "-s FORCE_FILESYSTEM=1"
-    "-s EXPORTED_RUNTIME_METHODS=['ccall','cwrap','FS','MEMFS']"
-    "-s EXPORT_NAME=loadMujoco"
-    "-gsource-map"
-    "-g"
-    "--emit-tsd mujoco_wasm_benchmark.d.ts"
-)
-string (REPLACE ";" " " EMCC_LINKER_FLAGS_STR "${EMCC_LINKER_FLAGS}")
-
-add_executable(mujoco_wasm_benchmark ${MUJOCO_WASM_FILES})
-
-set_target_properties(mujoco_wasm_benchmark PROPERTIES LINK_FLAGS "${EMCC_LINKER_FLAGS_STR}")
-
-# Link the mujoco library as a whole archive to avoid losing plugin
-# registration such as obj_decoder and stl_decoder.
-target_link_libraries(mujoco_wasm_benchmark PRIVATE
-    -Wl,--whole-archive mujoco -Wl,--no-whole-archive
-    ccd lodepng tinyxml2 qhullstatic_r
-)
-
-install(TARGETS mujoco_wasm_benchmark DESTINATION ${DIVISIBLE_INSTALL_BIN_DIR})