Build: Build LZMA1/2 presets also when only decoder is wanted.

People shouldn't rely on the presets when decoding raw streams,
but xz uses the presets as the starting point for raw decoder
options anyway.

lzma_encocder_presets.c was renamed to lzma_presets.c to
make it clear it's not used solely by the encoder code.

src/liblzma/lzma/Makefile.inc

@@ -9,12 +9,16 @@ EXTRA_DIST += lzma/fastpos_tablegen.c
 
 liblzma_la_SOURCES += lzma/lzma_common.h
 
+if COND_FILTER_LZMA1
+liblzma_la_SOURCES += \
+	lzma/lzma_presets.c
+endif
+
 if COND_ENCODER_LZMA1
 liblzma_la_SOURCES += \
 	lzma/fastpos.h \
 	lzma/lzma_encoder.h \
 	lzma/lzma_encoder.c \
-	lzma/lzma_encoder_presets.c \
 	lzma/lzma_encoder_private.h \
 	lzma/lzma_encoder_optimum_fast.c \
 	lzma/lzma_encoder_optimum_normal.c

src/liblzma/lzma/lzma_presets.c

@@ -1,7 +1,8 @@
 ///////////////////////////////////////////////////////////////////////////////
 //
-/// \file       lzma_encoder_presets.c
+/// \file       lzma_presets.c
 /// \brief      Encoder presets
+/// \note       xz needs this even when only decoding is enabled.
 //
 //  Author:     Lasse Collin
 //