feat(third_party/bazel): Check in rules_haskell from Tweag

third_party/bazel/rules_haskell/haskell/ghc.BUILD

@@ -0,0 +1,83 @@
+package(default_visibility = ["//visibility:public"])
+
+filegroup(
+    name = "bin",
+    srcs = glob(["bin/*"]),
+)
+
+cc_library(
+    name = "threaded-rts",
+    srcs = glob(
+        ["lib/ghc-*/rts/libHSrts_thr-ghc*." + ext for ext in [
+            "so",
+            "dylib",
+        ]] +
+        # dependency of `libHSrts_thr_ghc*`
+        # globbing on the `so` version to stay working when they update
+        [
+            "lib/ghc-*/rts/libffi.so.*",
+        ],
+    ),
+    hdrs = glob(["lib/ghc-*/include/**/*.h"]),
+    strip_include_prefix = glob(
+        ["lib/ghc-*/include"],
+        exclude_directories = 0,
+    )[0],
+)
+
+# TODO: detect this more automatically.
+cc_library(
+    name = "unix-includes",
+    hdrs = glob(["lib/ghc-*/unix-*/include/*.h"]),
+    includes = glob(
+        ["lib/ghc-*/unix-*/include"],
+        exclude_directories = 0,
+    ),
+)
+
+# This is needed for Hazel targets.
+cc_library(
+    name = "rts-headers",
+    hdrs = glob([
+        "lib/ghc-*/include/**/*.h",
+        "lib/include/**/*.h",
+    ]),
+    includes = glob(
+        [
+            "lib/ghc-*/include",
+            "lib/include",
+        ],
+        exclude_directories = 0,
+    ),
+)
+
+# Expose embedded MinGW toolchain when on Windows.
+
+filegroup(
+    name = "empty",
+    srcs = [],
+)
+
+cc_toolchain_suite(
+    name = "toolchain",
+    toolchains = {
+        "x64_windows": ":cc-compiler-mingw64",
+        "x64_windows|ghc-mingw-gcc": ":cc-compiler-mingw64",
+    },
+)
+
+# Keep in sync with @bazel_tools//cpp:cc-compiler-x64_windows definition.
+cc_toolchain(
+    name = "cc-compiler-mingw64",
+    all_files = ":empty",
+    ar_files = ":empty",
+    as_files = ":empty",
+    compiler_files = ":empty",
+    cpu = "x64_windows",
+    dwp_files = ":empty",
+    linker_files = ":empty",
+    objcopy_files = ":empty",
+    strip_files = ":empty",
+    supports_param_files = 0,
+    toolchain_identifier = "ghc_windows_mingw64",
+)