[saddamr3e]

1. TIntermediate::promoteBinary classifies operands with isVector()/isMatrix(), and a GL_EXT_long_vector type is neither, so vector<float, 8> + vec4, mat4 * vector<float, 8> and vector<float, 4> * vec4 are accepted as scalar operations.
2. TIntermConstantUnion::fold then iterates over the left operand's component count and indexes the shorter right operand's TConstUnionArray past its end: UBSan reports an invalid TBasicType load at ConstantUnion.h:441, debug asserts, release folds the stray bytes into the emitted constant. The non-constant forms hit the isScalar assert in createBinaryOperation or emit an OpFAdd that spirv-val rejects.
   Rejected a long vector mixed with a vector or matrix unless the existing same-size vectorAndLongVectorMatch rule applies, and made that matching pair a component-wise product instead of VectorTimesScalar. Added spv.longVectorBadParams.mixedShape.comp for the rejected forms and extended spv.longVectorLiteral234.comp with the same-size multiply; both crash the unpatched debug build, and ctest is green in Debug+ASan/UBSan and Release.