wasm: add more debugging information

This also fixes source maps not getting created in debug mode.

Pick-to: 5.15
Fixes: QTBUG-83607
Change-Id: I3ed388c4fef6c286fa452a1c700fa65c2a8f9529
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

mkspecs/wasm-emscripten/qmake.conf

@@ -53,9 +53,10 @@ EMCC_COMMON_LFLAGS_DEBUG = \
     # -s SYSCALL_DEBUG=1 \ #print out sys calls, verbose
     # -s FS_LOG=1 \ #print out filesystem ops, verbose
     # -s SOCKET_DEBUG \ #print out socket,network data transfer
-    -s GL_DEBUG=1
+    -s GL_DEBUG=1 \
+    --profiling-funcs
 
-QMAKE_LFLAGS_DEBUG  += -g
+QMAKE_LFLAGS_DEBUG  += -g4
 QMAKE_LFLAGS_RELEASE  += -O2
 
 QMAKE_COMPILER         += emscripten