Set alignment of .llvmbc and .llvmcmd to 1

Otherwise their alignment is dependent on the size of the section.  If the size
is large than 16, the alignment will be 16.

16 is a bad choice for both .llvmbc and .llvmcmd because the padding between two
contributions from input sections is of a variable size.

A bitstream is actually guaranteed to be 4-byte aligned, but consumers don't
need this property.