Revert "Switch cc's use of bison and flex to prebuilt_build_tool"

Revert submission 1366377-prebuilt_build_tool_make

Reason for revert: breaks build
Reverted Changes:
I20bf062bb:Export prebuilt tools to Make
I4bb526492:Move some prebuilt build tool configs to Soong
I195b68813:Support per-module MakeVars
Ibcb257e7b:Fix dependency loop with flex
I6150f0f39:Switch cc's use of bison and flex to prebuilt_buil...
I6939451b8:Reland "Use genrules to build a consistent awk."
Idee60640f:Add prebuilt_build_tool modules for genrule use
I00893172b:Rename bison to bison_bin
I82c26be1c:Add prebuilt_build_tool to allow genrules to use p...

Change-Id: I1ca553ffe4b09250a441b9bc477c3ba98c6f6549
diff --git a/cc/compiler.go b/cc/compiler.go
index ba14dd5..d5ea2c3 100644
--- a/cc/compiler.go
+++ b/cc/compiler.go
@@ -251,14 +251,6 @@
 		deps.StaticLibs = append(deps.StaticLibs, "libomp")
 	}
 
-	if compiler.hasSrcExt(".y") || compiler.hasSrcExt(".yy") {
-		deps.Tools = append(deps.Tools, "bison", "m4")
-	}
-
-	if compiler.hasSrcExt(".l") || compiler.hasSrcExt(".ll") {
-		deps.Tools = append(deps.Tools, "flex", "m4")
-	}
-
 	return deps
 }
 
@@ -589,7 +581,7 @@
 
 	srcs := append(android.Paths(nil), compiler.srcsBeforeGen...)
 
-	srcs, genDeps := genSources(ctx, srcs, buildFlags, deps.Tools)
+	srcs, genDeps := genSources(ctx, srcs, buildFlags)
 	pathDeps = append(pathDeps, genDeps...)
 
 	compiler.pathDeps = pathDeps