enable exceptions in build flags

Author: me-no-dev

platform.txt

@@ -28,7 +28,7 @@ compiler.c.cmd=xtensa-esp32-elf-gcc
 compiler.c.flags=-std=gnu99 -Os -g3 -fstack-protector -ffunction-sections -fdata-sections -fstrict-volatile-bitfields -mlongcalls -nostdlib -Wpointer-arith {compiler.warning_flags} -Wno-error=unused-function -Wno-error=unused-but-set-variable -Wno-error=unused-variable -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-sign-compare -Wno-old-style-declaration -MMD -c
 
 compiler.cpp.cmd=xtensa-esp32-elf-g++
-compiler.cpp.flags=-std=gnu++11 -fno-exceptions -Os -g3 -Wpointer-arith -fstack-protector -ffunction-sections -fdata-sections -fstrict-volatile-bitfields -mlongcalls -nostdlib {compiler.warning_flags} -Wno-error=unused-function -Wno-error=unused-but-set-variable -Wno-error=unused-variable -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-sign-compare -fno-rtti -MMD -c
+compiler.cpp.flags=-std=gnu++11 -fno-exceptions -Os -g3 -Wpointer-arith -fexceptions -fstack-protector -ffunction-sections -fdata-sections -fstrict-volatile-bitfields -mlongcalls -nostdlib {compiler.warning_flags} -Wno-error=unused-function -Wno-error=unused-but-set-variable -Wno-error=unused-variable -Wno-error=deprecated-declarations -Wno-unused-parameter -Wno-sign-compare -fno-rtti -MMD -c
 
 compiler.S.cmd=xtensa-esp32-elf-gcc
 compiler.S.flags=-c -g3 -x assembler-with-cpp -MMD -mlongcalls