gdb/configure: realign the AC_ARG_ENABLE(sim, ....) block

Following the suggestion in this review comment:

  https://inbox.sourceware.org/gdb-patches/9420bbb0-2614-4847-9157-8562f8a62d03@simark.ca

this commit realigns the AC_ARG_ENABLE(sim, ....) block.  I've added
additional [...] quoting in a couple of places, which is inline with
how other AC_ARG_ENABLE blocks are formatted within GDB's configure.ac
file.

There should be no change in how GDB configures or builds after this
commit.
2 files changed