QLibraryInfo: fix GCC ubsan build

Same bug that plagues tst_qbytearrayview.cpp, similar fix: drop the
static checks for GCC. Except that here, following code uses the
variable, so it needs to exist. Fortunately, the GCC ubsan bug does
not affect construction from a string literal, so we can use
that. This is losing the position checking for "." in qtConfEntries,
but the the original author (Thiago) informs me that was just a way to
save two bytes, we don't actually need the assertions, so remove them.

As a drive-by, remove the unneeded, and potentially pessimizing
(forces the compiler to allocate storage for it in the binary), static
keyword from the constexpr variable, which should more than make up
for the extra two octets.

Pick-to: 6.6 6.5
Change-Id: I88397ac61c5cd8f53d39e957212c895239aace04
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/global/qlibraryinfo.cpp

@@ -475,9 +475,7 @@ QLibraryInfoPrivate::LocationInfo QLibraryInfoPrivate::locationInfo(QLibraryInfo
         "Examples", "examples",
         "Tests", "tests"
     );
-    static constexpr QByteArrayView dot = qtConfEntries.viewAt(1);
-    static_assert(dot.size() == 1);
-    static_assert(dot[0] == '.');
+    constexpr QByteArrayView dot{"."};
 
     LocationInfo result;