s390x: prepare for upstreaming

disable autodetection for s390x, since it still a work in progress
and not yet optimized, but add put_label and support for alternate
allocators while rebasing/updating the code base.

adjust syntax to match the style used by the rest of the codebase
for easy of maintenance.

Makefile

@@ -38,6 +38,7 @@ SLJIT_LIR_FILES = $(SRCDIR)/sljitLir.c $(SRCDIR)/sljitUtils.c \
 	$(SRCDIR)/sljitNativePPC_common.c $(SRCDIR)/sljitNativePPC_32.c $(SRCDIR)/sljitNativePPC_64.c \
 	$(SRCDIR)/sljitNativeSPARC_common.c $(SRCDIR)/sljitNativeSPARC_32.c \
 	$(SRCDIR)/sljitNativeTILEGX_64.c \
+	$(SRCDIR)/sljitNativeS390X.c \
 	$(SRCDIR)/sljitNativeX86_common.c $(SRCDIR)/sljitNativeX86_32.c $(SRCDIR)/sljitNativeX86_64.c
 
 .PHONY: all clean examples

sljit_src/sljitConfigInternal.h

@@ -162,8 +162,6 @@ extern "C" {
 #define SLJIT_CONFIG_SPARC_32 1
 #elif defined(__tilegx__)
 #define SLJIT_CONFIG_TILEGX 1
-#elif defined(__s390x__)
-#define SLJIT_CONFIG_S390X 1
 #else
 /* Unsupported architecture */
 #define SLJIT_CONFIG_UNSUPPORTED 1

sljit_src/sljitLir.c

@@ -633,7 +633,10 @@ static SLJIT_INLINE sljit_s32 get_arg_count(sljit_s32 arg_types)
 	return arg_count;
 }
 
-#if !(defined SLJIT_CONFIG_X86 && SLJIT_CONFIG_X86)
+
+/* Only used in RISC architectures where the instruction size is constant */
+#if !(defined SLJIT_CONFIG_X86 && SLJIT_CONFIG_X86) \
+	&& !(defined SLJIT_CONFIG_S390X && SLJIT_CONFIG_S390X)
 
 static SLJIT_INLINE sljit_uw compute_next_addr(struct sljit_label *label, struct sljit_jump *jump,
 	struct sljit_const *const_, struct sljit_put_label *put_label)
@@ -655,7 +658,7 @@ static SLJIT_INLINE sljit_uw compute_next_addr(struct sljit_label *label, struct
 	return result;
 }
 
-#endif /* !SLJIT_CONFIG_X86 */
+#endif /* !SLJIT_CONFIG_X86 && !SLJIT_CONFIG_S390X */
 
 static SLJIT_INLINE void set_emit_enter(struct sljit_compiler *compiler,
 	sljit_s32 options, sljit_s32 args, sljit_s32 scratches, sljit_s32 saveds,