package/fluent-bit: needs arch support and C++ for wasm

See:
https://github.com/fluent/fluent-bit/tree/master/lib/wasm-micro-runtime-WAMR-1.1.1#supported-architectures-and-platforms

MIPS & RISCV32 are mentioned in the supported list,
but that seems to be wrong, so excluded those.

Fixes:
- http://autobuild.buildroot.org/results/dfb/dfb8f71d7e016cdfd3beb4b8196081898bd49ae2/build-end.log
- http://autobuild.buildroot.org/results/ecf/ecfe7b67af68cd7f397a50360900cd9a7afc830e/build-end.log

Signed-off-by: Thomas Devoogdt <thomas.devoogdt@gmail.com>
[Peter: Move arch dependency to _WASM_ARCH_SUPPORTS blind option, add help
	text, use normal style for prompt and fix indentation]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/fluent-bit/Config.in

@@ -8,5 +8,26 @@ config BR2_PACKAGE_FLUENT_BIT
 
 	  https://github.com/fluent/fluent-bit
 
+if BR2_PACKAGE_FLUENT_BIT
+
+config BR2_PACKAGE_FLUENT_BIT_WASM_ARCH_SUPPORTS
+	bool
+	# see lib/wasm-micro-runtime-WAMR-1.1.1/README.md#supported-architectures-and-platforms
+	default y if BR2_arc
+	default y if BR2_arm || BR2_armeb
+	default y if BR2_aarch64 || BR2_aarch64_be
+	default y if BR2_i386 || BR2_x86_64
+	default y if BR2_RISCV_64
+	default y if BR2_xtensa
+
+config BR2_PACKAGE_FLUENT_BIT_WASM
+	bool "wasm runtime support"
+	depends on BR2_INSTALL_LIBSTDCPP
+	depends on BR2_PACKAGE_FLUENT_BIT_WASM_ARCH_SUPPORTS
+	help
+	  Support for WASM-based plugins.
+
+endif
+
 comment "fluent-bit needs a glibc toolchain"
 	depends on !BR2_TOOLCHAIN_USES_GLIBC

package/fluent-bit/fluent-bit.mk

@@ -17,6 +17,12 @@ FLUENT_BIT_CONF_OPTS += \
 	-DFLB_CHUNK_TRACE=No \
 	-DFLB_BACKTRACE=No
 
+ifeq ($(BR2_PACKAGE_FLUENT_BIT_WASM),y)
+FLUENT_BIT_CONF_OPTS += -DFLB_WASM=Yes
+else
+FLUENT_BIT_CONF_OPTS += -DFLB_WASM=No
+endif
+
 ifeq ($(BR2_PACKAGE_LUAJIT),y)
 FLUENT_BIT_CONF_OPTS += -DFLB_LUAJIT=Yes
 FLUENT_BIT_DEPENDENCIES += luajit