stoc: try to throw more informative exceptions

... from IdlInterfaceMethodImpl::invoke(), which is somewhere involved
in BASIC calls.

Change-Id: I739f70fec56ec9e4345511eefe41fd0f8df8bf6f
Reviewed-on: https://gerrit.libreoffice.org/33593Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>

stoc/source/corereflection/criface.cxx

@@ -650,7 +650,10 @@ Any SAL_CALL IdlInterfaceMethodImpl::invoke( const Any & rObj, Sequence< Any > &
                 if (! bAssign)
                 {
                     IllegalArgumentException aExc(
-                        "cannot coerce argument type during corereflection call!",
+                        "cannot coerce argument type during corereflection call:"
+                        "\narg no.: " + OUString::number(nPos)
+                        + " expected: \"" + OUString(pTD->pTypeName)
+                        + "\" actual: \"" + OUString(pCppArgs[nPos].getValueTypeRef()->pTypeName),
                         *o3tl::doAccess<Reference<XInterface>>(rObj), (sal_Int16)nPos );
 
                     // cleanup