wasm: Enable asyncify for tests

Since a good number of tests use exec and friends, we want to use
asyncify for them. Asyncify is still possible to enable universally
with device options.

Change-Id: I0916f55328c98f2ba179cda3757eeee9d27f3e47
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

cmake/QtTestHelpers.cmake

@@ -558,6 +558,11 @@ function(qt_internal_add_test name)
         # TODO: Add functionality to specify browser
         list(APPEND extra_test_args "--browser=chrome")
 
+        # We always want to enable asyncify for tests, as some of them use exec
+        # Optimize for size (-Os), since asyncify tends to make the resulting
+        # binary very large
+        target_link_options("${name}" PRIVATE "SHELL:-s ASYNCIFY" "-Os")
+
         # This tells cmake to run the tests with this script, since wasm files can't be
         # executed directly
         set_property(TARGET "${name}" PROPERTY CROSSCOMPILING_EMULATOR "emrun")

cmake/QtWasmHelpers.cmake

@@ -70,7 +70,6 @@ function (qt_internal_setup_wasm_target_properties wasmTarget)
     # target_link_options("${wasmTarget}" INTERFACE "SHELL:-s SOCKET_DEBUG") # print out socket,network data transfer
 
     if ("QT_EMSCRIPTEN_ASYNCIFY=1" IN_LIST QT_QMAKE_DEVICE_OPTIONS)
-
         # Emscripten recommends building with optimizations when using asyncify
         # in order to reduce wasm file size, and may also generate broken wasm
         # (with "wasm validation error: too many locals" type errors) if optimizations