wasm: building with emscripten 1.38.26 results in errors

emscripten 1.38.26 removed 'fake' sse/simd support, which removed x86intrin.h file

https://github.com/emscripten-core/emscripten/pull/7924/commits/a0deb93580bded32549daacd9c4a0835b7a1aaca

Fixing the build by this patch:

diff --git a/src/corelib/tools/qsimd_p.h b/src/corelib/tools/qsimd_p.h
index c36e1e484f..9ec1f5c884 100644
— a/src/corelib/tools/qsimd_p.h
+++ b/src/corelib/tools/qsimd_p.h
@@ -191,7 +191,7 @@

1. include <immintrin.h>
2. endif

• 1. if defined(Q_CC_GNU) && !defined(Q_CC_INTEL)
     +# if defined(Q_CC_GNU) && !defined(Q_CC_INTEL) && !defined(Q_OS_WASM)
     // GCC 4.4 and Clang 2.8 added a few more intrinsics there

1. include <x86intrin.h>
2. endif

results in an error where the qt app does not load, and shows:

Application exit(random_device)

But using a default shell html shell_minimal.html

QMAKE_LFLAGS += --shell-file ~/emsdk/emscripten/1.38.26/src/shell_minimal.html

Loads the app correctly.

So there are two issues:

1. qsimd_p.h
2. emscriptens library_fs.js