Wasm: enable thread support

configure.json: Make the “thread” feature be allowed
for wasm but disabled by default.

Change qmake.conf and wasm.prf to enable Emscripten
pthreads mode:
- Add USE_PTHREADS=1 linker flag
- Add PTHREAD_POOL_SIZE linker flag with a default pool size (4).
- Add TOTAL_MEMORY linker flag to set available memory (1GB)

It is possible to override options such as PTHREAD_POOL_SIZE
from the application .pro file using QMAKE_WASM_PTHREAD_POOL_SIZE
To change TOTAL_MEMORY, use QMAKE_WASM_TOTAL_MEMORY

Make qtloader.js work in pthreads mode:
- The Module.instantiateWasm callback must provide the module
  in addition to the instance to Emscripten.
- Set Module.mainScriptUrlOrBlob so that the pthreads web workers
  can access the main script

Task-number: QTBUG-64625
Change-Id: I1ab5a559ec97c27c5fc24500ba5f863bcd275141
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
Reviewed-by: Lorn Potter <lorn.potter@gmail.com>

0 files changed, 0 insertions, 0 deletions