fix platform file to support Arduino Eclipse Plugin

fixes #2

platform.txt

@@ -17,6 +17,9 @@ compiler.cpreprocessor.flags=-D__ets__ -DICACHE_FLASH "-I{compiler.sdk.path}/inc
 compiler.c.cmd=xtensa-lx106-elf-gcc
 compiler.c.flags=-c -Os -Wpointer-arith -Wno-implicit-function-declaration -Wl,-EL -fno-inline-functions -nostdlib -mlongcalls -mtext-section-literals -MMD -std=c99
 
+compiler.S.cmd=xtensa-lx106-elf-gcc
+compiler.S.flags=-c -g -x assembler-with-cpp -MMD
+
 compiler.c.elf.ldscript=eagle.app.v6.ld
 compiler.c.elf.flags=-nostdlib -Wl,--no-check-sections -u call_user_start -Wl,-static "-L{compiler.sdk.path}/lib" "-L{compiler.sdk.path}/ld" "-T{compiler.c.elf.ldscript}"
 compiler.c.elf.cmd=xtensa-lx106-elf-gcc
@@ -57,7 +60,7 @@ recipe.c.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.fla
 recipe.cpp.o.pattern="{compiler.path}{compiler.cpp.cmd}" {compiler.cpreprocessor.flags} {compiler.cpp.flags} -DF_CPU={build.f_cpu} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} {compiler.cpp.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Compile S files
-recipe.S.o.pattern="{compiler.path}{compiler.as.cmd}"  -o "{object_file}" "{source_file}"
+recipe.S.o.pattern="{compiler.path}{compiler.c.cmd}" {compiler.cpreprocessor.flags} {compiler.S.flags} -DF_CPU={build.f_cpu} -DARDUINO={runtime.ide.version} -DARDUINO_{build.board} -DARDUINO_ARCH_{build.arch} {compiler.c.extra_flags} {build.extra_flags} {includes} "{source_file}" -o "{object_file}"
 
 ## Create archives
 recipe.ar.pattern="{compiler.path}{compiler.ar.cmd}" {compiler.ar.flags} {compiler.ar.extra_flags} "{build.path}/{archive_file}" "{object_file}"