[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.

3 files changed, 3 insertions, 3 deletions

diff --git a/gdb/stubs/i386-stub.c b/gdb/stubs/i386-stub.c
index 04996b7..74fe476 100644
--- a/gdb/stubs/i386-stub.c
+++ b/gdb/stubs/i386-stub.c
@@ -46,7 +46,7 @@
  *
  *  Because gdb will sometimes write to the stack area to execute function
  *  calls, this program cannot rely on using the supervisor stack so it
- *  uses it's own stack area reserved in the int array remcomStack.
+ *  uses its own stack area reserved in the int array remcomStack.
  *
  *************
  *
diff --git a/gdb/stubs/m32r-stub.c b/gdb/stubs/m32r-stub.c
index 7f0614a..90754e3 100644
--- a/gdb/stubs/m32r-stub.c
+++ b/gdb/stubs/m32r-stub.c
@@ -46,7 +46,7 @@
  *
  *  Because gdb will sometimes write to the stack area to execute function
  *  calls, this program cannot rely on using the supervisor stack so it
- *  uses it's own stack area reserved in the int array remcomStack.
+ *  uses its own stack area reserved in the int array remcomStack.
  *
  *************
  *
diff --git a/gdb/stubs/m68k-stub.c b/gdb/stubs/m68k-stub.c
index 47eca00..1598422 100644
--- a/gdb/stubs/m68k-stub.c
+++ b/gdb/stubs/m68k-stub.c
@@ -62,7 +62,7 @@
  * 
  *  Because gdb will sometimes write to the stack area to execute function
  *  calls, this program cannot rely on using the supervisor stack so it
- *  uses it's own stack area reserved in the int array remcomStack.  
+ *  uses its own stack area reserved in the int array remcomStack.
  * 
  *************
  *