replaces implicit passes array registed at runtime with explicit function calls; simplify compilation pipeline (#21444)

* abolish using passes in the compiler; simplify compilation pipeline

* duplicate code

* Really cool to have the same signature...

* haul

* unify other backends

* refactor process

* introduce PipelinePhase

* refactor compiler

* fixes passes

* fixes nimsuggest

* add a sentinel

* enable docs checkj

* activate doc testing

* clean up

* complete cleanups

compiler/modulegraphs.nim

@@ -57,6 +57,18 @@ type
     sym*: PSym
     info*: TLineInfo
 
+  PipelinePass* = enum
+    NonePass
+    SemPass
+    JSgenPass
+    CgenPass
+    EvalPass
+    InterpreterPass
+    GenDependPass
+    Docgen2TexPass
+    Docgen2JsonPass
+    Docgen2Pass
+
   ModuleGraph* {.acyclic.} = ref object
     ifaces*: seq[Iface]  ## indexed by int32 fileIdx
     packed*: PackedModuleGraph
@@ -104,6 +116,7 @@ type
     cacheCounters*: Table[string, BiggestInt] # IC: implemented
     cacheTables*: Table[string, BTree[string, PNode]] # IC: implemented
     passes*: seq[TPass]
+    pipelinePass*: PipelinePass
     onDefinition*: proc (graph: ModuleGraph; s: PSym; info: TLineInfo) {.nimcall.}
     onDefinitionResolveForward*: proc (graph: ModuleGraph; s: PSym; info: TLineInfo) {.nimcall.}
     onUsage*: proc (graph: ModuleGraph; s: PSym; info: TLineInfo) {.nimcall.}