* configure.ac: Check alignment of uint64_t, and also use AC_SUBST
for use in config.m4.in.

Rev: nettle/config.m4.in:1.2
Rev: nettle/configure.ac:1.48

* configure.ac (ASM_ALIGN_LOG): Check if .align directive is
logarithmic.
* asm.m4 (ALIGN): New macro. Takes a logarithmic argument, and
expands to a .align directive.

Rev: src/nettle/asm.m4:1.16
Rev: src/nettle/config.m4.in:1.6

Rev: src/nettle/config.m4.in:1.5

substitute the value of ASM_MARK_NOEXEC_STACK at the end of each
assembler file.

Rev: src/nettle/config.m4.in:1.4

Rev: src/nettle/config.m4.in:1.3

Rev: src/nettle/config.m4.in:1.2

Rev: src/nettle/config.m4.in:1.1