[gdb] Fix grammar in comments and docs

Fix grammar in some comments and docs:
- machines that doesn't -> machines that don't
- its a -> it's a
- its the -> it's the
- if does its not -> if it does it's not
- one more instructions if doesn't match ->
  one more instruction if it doesn't match
- it's own -> its own
- it's first -> its first
- it's pointer -> its pointer

I also came across "it's performance" in gdb/stubs/*-stub.c in the HP public
domain notice, I've left that alone.

Tested on x86_64-linux.

1 files changed, 1 insertions, 1 deletions

diff --git a/gdb/ppc-linux-nat.c b/gdb/ppc-linux-nat.c
index cb70b58..55dcda9 100644
--- a/gdb/ppc-linux-nat.c
+++ b/gdb/ppc-linux-nat.c
@@ -2126,7 +2126,7 @@ ppc_linux_nat_target::region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
 	  /* DAWR interface allows to watch up to 512 byte wide ranges.  */
 	  region_size = 512;
 	  /* DAWR interface allows to watch up to 512 byte wide ranges which
-	     can't cross a 512 byte boundary on machines that doesn't have a
+	     can't cross a 512 byte boundary on machines that don't have a
 	     second DAWR (P9 or less).  */
 	  if (!(hwdebug_info.features & PPC_DEBUG_FEATURE_DATA_BP_ARCH_31))
 	    region_align = 512;