Fix random number generation and floating point comparison in matrix-types-spec.cpp

The testsuite is failing on PowerPC buildbots due to
Looks like we are using wrong type generator for double.

We are also using EXPECT_MATRIX_EQ to do binary comparision of
floating point values before and afer multiplication. And there might be
small differences but within tolerance allowance.

Reviewed By: fhahn

Differential Revision:
1 file changed