Disable ICC warning 3373

This warning does not make sense. it seems to trigger when in code like
the following in template functions:

    auto x = 1, y = 2;

3373: nonstandard use of "auto" to both deduce the type from an
initializer and to announce a trailing return type

Other reports on the Internet indicate that no one understands what
triggers this warning and have just worked around it. Additionally, the
same warning exists on other compilers with the same text, so it's
likely come from the EDG front-end. This has been reported to Intel.

Change-Id: I73fa1e59a4844c43a109fffd148d45065ab69eff
Intel-Issue-ID: 6000164202
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

mkspecs/linux-icc/qmake.conf

@@ -14,7 +14,7 @@ QMAKE_YACCFLAGS         = -d
 QMAKE_CFLAGS            =
 QMAKE_CFLAGS_APP        = -fPIC
 QMAKE_CFLAGS_DEPS       = -M
-QMAKE_CFLAGS_WARN_ON    = -w1 -Wall -Wcheck -wd1572,873,2259,2261
+QMAKE_CFLAGS_WARN_ON    = -w1 -Wall -Wcheck -wd1572,873,2259,2261,3373
 QMAKE_CFLAGS_WARN_OFF   = -w
 QMAKE_CFLAGS_RELEASE    = -O2 -falign-functions=16 -ansi-alias -fstrict-aliasing
 QMAKE_CFLAGS_DEBUG      = -O0 -g

mkspecs/macx-icc/qmake.conf

@@ -14,7 +14,7 @@ QMAKE_COMPILER          = gcc clang intel_icc   # icc pretends to be gcc and cla
 QMAKE_CC                = icc
 QMAKE_CFLAGS            =
 QMAKE_CFLAGS_DEPS       = -M
-QMAKE_CFLAGS_WARN_ON    = -w1 -Wcheck -wd654,1572,411,873,1125,2259,2261,3280
+QMAKE_CFLAGS_WARN_ON    = -w1 -Wcheck -wd654,1572,411,873,1125,2259,2261,3280,3373
 QMAKE_CFLAGS_WARN_OFF   = -w
 QMAKE_CFLAGS_RELEASE    =
 QMAKE_CFLAGS_DEBUG      = -g

mkspecs/win32-icc/qmake.conf

@@ -19,7 +19,7 @@ QMAKE_LEX               = flex
 QMAKE_LEXFLAGS          =
 QMAKE_YACC              = bison -y
 QMAKE_YACCFLAGS         = -d
-QMAKE_CFLAGS            = -nologo -Zm200 /Qprec /Qwd1744,1738,809
+QMAKE_CFLAGS            = -nologo -Zm200 /Qprec /Qwd1744,1738,809,3373
 QMAKE_CFLAGS_WARN_ON    = -W3 /Qwd673
 QMAKE_CFLAGS_WARN_OFF   = -W0 /Qwd673
 QMAKE_CFLAGS_RELEASE    = -O2 -MD