Move fp16 dependency to Bazel & patch v8

WORKSPACE

@@ -190,6 +190,12 @@ git_repository(
     remote = "https://chromium.googlesource.com/chromium/src/third_party/abseil-cpp.git",
 )
 
+git_repository(
+    name = "fp16",
+    commit = "0a92994d729ff76a58f692d3028ca1b64b145d91",
+    remote = "https://chromium.googlesource.com/external/github.com/Maratyszcza/FP16.git"
+)
+
 # Bindings for abseil libraries used by V8
 [
     bind(
@@ -449,7 +455,8 @@ http_archive(
         "//:patches/v8/0012-Always-enable-continuation-preserved-data-in-the-bui.patch",
         "//:patches/v8/0013-increase-visibility-of-virtual-method.patch",
         "//:patches/v8/0014-Add-ValueSerializer-SetTreatFunctionsAsHostObjects.patch",
-        "//:patches/v8/0015-Set-torque-generator-path-to-external-v8.-This-allow.patch"
+        "//:patches/v8/0015-Set-torque-generator-path-to-external-v8.-This-allow.patch",
+        "//:patches/v8/0016-Modify-where-to-look-for-fp16-dependency.-This-depen.patch"
     ],
     integrity = "sha256-C6bsXXbKgeCxmG1VNO/LScaPq0HVlmofpVHJ5kswoLg=",
     strip_prefix = "v8-12.4.254.11",

patches/v8/0015-Set-torque-generator-path-to-external-v8.-This-allow.patch

@@ -17,6 +17,6 @@ index e55defede9fed3eea9348bd7bd50d98f688a2a7b..faeef2b2ed71b4784050451a61a16feb
  def _torque_files_impl(ctx):
 -    v8root = "."
 +    v8root = "external/v8"
-
+ 
      # Arguments
      args = []

patches/v8/0016-Modify-where-to-look-for-fp16-dependency.-This-depen.patch

@@ -0,0 +1,30 @@
+From 76d8cc9d39d0798155d0a7df176b9d3a1bdb7a55 Mon Sep 17 00:00:00 2001
+From: Garrett Gu <[email protected]>
+Date: Mon, 22 Apr 2024 10:10:21 -0500
+Subject: =?UTF-8?q?Modify=20where=20to=20look=20for=20fp16=20dependency.?=
+ =?UTF-8?q?=20This=20dependency=20is=20normally=20downloaded=20by=20gn=20b?=
+ =?UTF-8?q?ut=20we=0Aneed=20to=20fetch=20it=20in=20Bazel.=20We=20do=20so?=
+ =?UTF-8?q?=20in=20the=20workerd=20repo=20in=20the=20WORKSPACE=20file.?=
+
+
+diff --git a/BUILD.bazel b/BUILD.bazel
+index f3e7958b39e5b7e42b06fad83a0bf6f7352ffd3c..acc8d6a9ed050ad95e799892a9df4be47203657b 100644
+--- a/BUILD.bazel
++++ b/BUILD.bazel
+@@ -3691,13 +3691,12 @@ filegroup(
+
+ v8_library(
+   name = "lib_fp16",
+-  srcs = ["third_party/fp16/src/include/fp16.h"],
+   hdrs = [
+-    "third_party/fp16/src/include/fp16/fp16.h",
+-    "third_party/fp16/src/include/fp16/bitcasts.h",
++    "@fp16//:src/include/fp16/fp16.h",
++    "@fp16//:src/include/fp16/bitcasts.h",
+   ],
+   includes = [
+-    "third_party/fp16/src/include",
++    "@fp16//:src/include",
+   ],
+ )
+