V6 regression on geometry of a SweptDiskSolid rebar element

[andyward]

Perhaps related (or in a similar area) to #550 - there's a regression in V6 calculating the geometry of this rebar:

Renders correctly in v4/5 and other IFC viewers

In v6 the IFCSWEPTDISKSOLID / COMPOSITECURVE seems incorrect

The same issue occurs in both v5 and v6 engine versions.

GL_ClippedReba-stripped.ifc.zip