Refactor the abstract domain of global init checker to compile http4s (#22179)

This is a draft PR that contains fixes to the initialization checker, so
that it can successfully check http4s in community-build

[test_scala2_library_tasty]

Author: olhotak

compiler/src/dotty/tools/dotc/transform/init/Objects.scala

@@ -1,9 +1,6 @@
 ## See #18882
 patmat.scala
 t9312.scala
-unapplySeq-implicit-arg.scala
-unapplySeq-implicit-arg2.scala
-unapplySeq-implicit-arg3.scala
 ScalaCheck.scala
 mutable-read8.scala
 TypeCast.scala

compiler/test/dotc/neg-init-global-scala2-library-tasty.excludelist

@@ -233,6 +233,10 @@ class CompilationTests {
     implicit val testGroup: TestGroup = TestGroup("checkInitGlobal")
     compileFilesInDir("tests/init-global/warn", defaultOptions.and("-Ysafe-init-global"), FileFilter.exclude(TestSources.negInitGlobalScala2LibraryTastyExcludelisted)).checkWarnings()
     compileFilesInDir("tests/init-global/pos", defaultOptions.and("-Ysafe-init-global", "-Xfatal-warnings"), FileFilter.exclude(TestSources.posInitGlobalScala2LibraryTastyExcludelisted)).checkCompile()
+    if Properties.usingScalaLibraryTasty && !Properties.usingScalaLibraryCCTasty then
+      compileFilesInDir("tests/init-global/warn-tasty", defaultOptions.and("-Ysafe-init-global"), FileFilter.exclude(TestSources.negInitGlobalScala2LibraryTastyExcludelisted)).checkWarnings()
+      compileFilesInDir("tests/init-global/pos-tasty", defaultOptions.and("-Ysafe-init-global", "-Xfatal-warnings"), FileFilter.exclude(TestSources.posInitGlobalScala2LibraryTastyExcludelisted)).checkCompile()
+    end if
   }
 
   // initialization tests

compiler/test/dotty/tools/dotc/CompilationTests.scala

@@ -0,0 +1,5 @@
+object A:
+  val a = f(10)
+  val b = -a
+  val c = b.toDouble
+  def f(x: Int) = x * 2 + 5

tests/init-global/pos/array-size-zero.scala renamed to tests/init-global/pos-tasty/array-size-zero.scala

@@ -0,0 +1,16 @@
+package p
+package object a {
+  val b = 10
+  implicit class CI(s: StringContext) {
+    def ci(args: Any*) = 10
+  }
+}
+
+import p.a._
+
+object A:
+  val f = b // p.a(ObjectRef(p.a)).b
+  def foo(s: String): String = s
+  val f1 = ci"a" // => p.a(Package(p).select(a)).CI(StringContext"a").ci()
+
+

tests/init-global/pos/arithmetic.scala

@@ -1,4 +1,4 @@
--- Warning: tests/init-global/warn/unapplySeq-implicit-arg.scala:11:20 -------------------------------------------------
+-- Warning: tests/init-global/warn-tasty/unapplySeq-implicit-arg.scala:11:20 -------------------------------------------
 11 |  val i2: Int = Seq(i2) match // warn
    |                    ^^
    |                    Access uninitialized field value i2. Calling trace: