Support Bazel 4.0.0

BAZEL_VERSION

@@ -1 +1 @@
-3.7.2
+4.0.0

README.md

@@ -107,7 +107,7 @@ I recommend you to build Bazel yourself, but if you really don't want to do it,
 When I was searching for a Bazel build for Raspberry Pi, I encountered the following projects, which I didn't use for various reasons but they gave some helpful background information about building Bazel on ARM:
 
 * [ochafik/rpi-raspbian-bazel](https://github.com/ochafik/rpi-raspbian-bazel): Seems to be unmaintained since end-2017.
-* [PINTO0309/Bazel_bin](https://github.com/PINTO0309/Bazel_bin): Has an impressive list of pre-built binaries for armhf, aarch64 and x86_64 as well as build instructions, but no releases more recent than 2.0.0.
+* [PINTO0309/Bazel_bin](https://github.com/PINTO0309/Bazel_bin): Has an impressive list of pre-built binaries for armhf, aarch64 and x86_64 as well as build instructions, but no recent releases when I started this project.
 * [This fix](https://github.com/bazelbuild/bazel/issues/11643#issuecomment-650573425) by [@redsigma](https://github.com/redsigma) was the key to solve my initial issue with building Bazel on ARM.
 
 ## License

patches/bazel-4.0.0-arm.patch

@@ -0,0 +1,33 @@
+diff -ruN bazel/tools/cpp/unix_cc_configure.bzl bazel-2/tools/cpp/unix_cc_configure.bzl
+--- bazel/tools/cpp/unix_cc_configure.bzl	1980-01-01 00:00:00.000000000 +0000
++++ bazel-2/tools/cpp/unix_cc_configure.bzl	2021-01-21 08:34:29.980980647 +0000
+@@ -388,7 +388,7 @@
+         False,
+     ), ":")
+
+-    bazel_linkopts = "-lstdc++:-lm"
++    bazel_linkopts = "-lstdc++:-lm -latomic"
+     bazel_linklibs = ""
+     if repository_ctx.flag_enabled("incompatible_linkopts_to_linklibs"):
+         bazel_linkopts, bazel_linklibs = bazel_linklibs, bazel_linkopts
+diff -ruN bazel/tools/jdk/BUILD bazel-2/tools/jdk/BUILD
+--- bazel/tools/jdk/BUILD	1980-01-01 00:00:00.000000000 +0000
++++ bazel-2/tools/jdk/BUILD	2021-01-21 08:35:35.219698682 +0000
+@@ -145,7 +145,7 @@
+         "//src/conditions:freebsd": [":jni_md_header-freebsd"],
+         "//src/conditions:openbsd": [":jni_md_header-openbsd"],
+         "//src/conditions:windows": [":jni_md_header-windows"],
+-        "//conditions:default": [],
++        "//conditions:default": [":jni_md_header-linux"],
+     }),
+     includes = ["include"] + select({
+         "//src/conditions:linux_aarch64": ["include/linux"],
+@@ -156,7 +156,7 @@
+         "//src/conditions:freebsd": ["include/freebsd"],
+         "//src/conditions:openbsd": ["include/openbsd"],
+         "//src/conditions:windows": ["include/win32"],
+-        "//conditions:default": [],
++        "//conditions:default": ["include/linux"],
+     }),
+ )
+