compiler.cfg.stacks.*: removing the adjust word which wasn't useful

basis/compiler/cfg/stacks/local/local-docs.factor

@@ -91,7 +91,6 @@ $nl
   translate-local-loc }
 "Words for writing the stack state:"
 { $subsections
-  adjust
   inc-stack
   modify-height
   replace-loc

basis/compiler/cfg/stacks/local/local.factor

@@ -14,9 +14,6 @@ IN: compiler.cfg.stacks.local
 : modify-height ( state loc -- )
     >loc< 0 1 ? rot nth [ + ] with map! drop ;
 
-: adjust ( state loc -- )
-    >loc< 0 1 ? rot nth dup first swapd + 0 rot set-nth ;
-
 : reset-emits ( state -- )
     [ 0 1 rot set-nth ] each ;
 

basis/compiler/cfg/stacks/stacks-docs.factor

@@ -16,8 +16,8 @@ HELP: end-stack-analysis
 { $description "Ends the stack analysis of the current cfg. This is the last step of the cfg construction (but comes before all optimization passes)." } ;
 
 HELP: adjust-d
-{ $values { "n" number } }
+{ $values { "n" integer } }
-{ $description "Changes the height of the current data stack. This word is called when other instructions which internally adjust the stack height are emitted, such as " { $link ##call } " and " { $link ##alien-invoke } "." } ;
+{ $description "Changes the current height of the data stack. The word is used when other instructions which adjust the stack height are emitted, such as " { $link ##call } " and " { $link ##alien-invoke } ". Since the stack height is adjusted without emitting " { ##inc } " instructions, the " { $link inc-stack } " word can't be used by them." } ;
 
 HELP: ds-drop
 { $description "Used to signal to the stack analysis that the datastacks height is decreased by one." } ;

basis/compiler/cfg/stacks/stacks-tests.factor

@@ -3,6 +3,15 @@ compiler.cfg.stacks compiler.cfg.stacks.local compiler.test kernel literals
 namespaces tools.test ;
 IN: compiler.cfg.stacks.tests
 
+! adjust-d
+{
+    { { 6 2 } { 3 4 } }
+    { { -4 2 } { 3 4 } }
+} [
+    { { 1 2 } { 3 4 } } [ height-state set 5 adjust-d ] keep
+    { { 1 2 } { 3 4 } } [ height-state set -5 adjust-d ] keep
+] unit-test
+
 {
     H{ { D: 1 4 } { D: 2 3 } { D: 0 5 } }
     { { 0 0 } { 0 0 } }

basis/compiler/cfg/stacks/stacks.factor

@@ -61,4 +61,4 @@ IN: compiler.cfg.stacks
     [ ds-pop ] dip call ds-push ; inline
 
 : adjust-d ( n -- )
-    <ds-loc> height-state get swap adjust ;
+    0 height-state get first [ + ] change-nth ;