runtime: Fix more typos (#13354)

* Fix more typos

* Fix typos in ignored runtime/ directory

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/asm68k.vim b/runtime/syntax/asm68k.vim
index e13dfe6..104887d 100644
--- a/runtime/syntax/asm68k.vim
+++ b/runtime/syntax/asm68k.vim
@@ -4,7 +4,7 @@
 " Last change:	2001 May 01
 "
 " This is incomplete.  In particular, support for 68020 and
-" up and 68851/68881 co-processors is partial or non-existant.
+" up and 68851/68881 co-processors is partial or non-existent.
 " Feel free to contribute...
 "
 
@@ -220,7 +220,7 @@
 syn match asm68kOperator	"="		" must be before other ops containing '='
 syn match asm68kOperator	">="
 syn match asm68kOperator	"<="
-syn match asm68kOperator	"=="		" operand existance - used in macro definitions
+syn match asm68kOperator	"=="		" operand existence - used in macro definitions
 
 " Condition code style operators
 syn match asm68kOperator	"<[CV][CS]>"