Add BPF architecture target support

BPF is a virtual machine and associated ISA that resides in the Linux
kernel.  Initially intended for user-level packet capture and filtering,
BPF is nowadays generalized to serve as a general-purpose infrastructure
also for non-networking purposes.

Signed-off-by: Cupertino Miranda <cupertino.miranda@oracle.com>

config/arch/bpf.in

@@ -0,0 +1,9 @@
+# BPF specific configuration file
+
+## no-package
+## select ARCH_SUPPORTS_EITHER_ENDIAN
+## select ARCH_DEFAULT_LE
+## select GCC_VERY_NEW
+## select BINUTILS_VERY_NEW
+##
+## help The BPF architecture.

samples/bpf-unknown-none/crosstool.config

@@ -0,0 +1,11 @@
+CT_CONFIG_VERSION="4"
+CT_ARCH_BPF=y
+CT_MULTILIB=n
+CT_TARGET_VENDOR="unknown"
+CT_TARGET_SYS=none
+CT_TARGET_ALIAS="bpf-unknown"
+CT_GCC_SRC_DEVEL=y
+CT_GCC_DEVEL_BRANCH="master"
+CT_BINUTILS_SRC_DEVEL=y
+CT_BINUTILS_DEVEL_BRANCH="master"
+CT_LIBC_NONE=y

samples/bpf-unknown-none/reported.by

@@ -0,0 +1,3 @@
+reporter_name="Cupertino Miranda"
+reporter_url=""
+reporter_comment="BPF toolchain"

scripts/build/arch/bpf.sh

@@ -0,0 +1,7 @@
+# Compute BPF-specific values
+
+CT_DoArchTupleValues() {
+        CT_TARGET_ARCH=bpf
+        CT_TARGET_VENDOR=unknown
+        CT_TARGET_SYS=none
+}