[iwyu] enable header include checks for torque

This also fixes all resulting failures.

Bug: v8:7965
Change-Id: I5451cdd3a3ec48c708107a22445808c268efe861
Reviewed-on: https://chromium-review.googlesource.com/1148336
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54643}

src/torque/global-context.h

@@ -17,6 +17,8 @@ namespace torque {
 class GlobalContext;
 class Scope;
 class TypeOracle;
+class Builtin;
+class Label;
 
 class Module {
  public:

src/torque/scope.h

@@ -17,6 +17,8 @@ namespace internal {
 namespace torque {
 
 class ScopeChain;
+class Variable;
+class Declarable;
 
 class Scope {
  public:

src/torque/types.h

@@ -34,6 +34,7 @@ static const char* const CONST_FLOAT64_TYPE_STRING = "constexpr float64";
 
 class Label;
 class Value;
+class Module;
 
 class TypeBase {
  public:

tools/generate-header-include-checks.py

@@ -122,7 +122,6 @@ AUTO_EXCLUDE = [
 ]
 AUTO_EXCLUDE_PATTERNS = [
   'src/base/atomicops_internals_.*',
-  'src/torque/.*',
 ] + [
   # platform-specific headers
   '\\b{}\\b'.format(p) for p in