text relocation for netbsd

netbsd does not allow text relocations in text segment.

tcc.h:
- Add data_ro_section
- Fix typo rela.plt

tccelf.c:
- Add data_ro_section
- Make bounds_section/lbounds_section rw
- Add GNU_RELRO section for data_ro_section/bounds_section/lbounds_section
- Fix relocation for __dso_handle in atexit()

tccgen.c:
- Use data_ro_section

x86_64-gen.c:
- Use R_X86_64_PC32 instead of R_X86_64_64 for bounds checking

tests/Makefile, tests/tests2/Makefile
- Enable dll tests for netbsd

tests/Makefile

@@ -64,17 +64,11 @@ endif
 ifeq ($(TARGETOS),OpenBSD)
 dlltest: CFLAGS+=-fno-stack-protector
 endif
-ifeq ($(TARGETOS),FreeBSD)
+ifneq (,$(filter FreeBSD NetBSD,$(TARGETOS)))
   # test3 has dlsym problems
   TESTS := $(filter-out test3,$(TESTS))
   TESTS += test1
 endif
-ifeq ($(TARGETOS),NetBSD)
-  # test3 has dlsym problems
-  # dlltest does not allow text relocations
-  TESTS := $(filter-out test3 dlltest,$(TESTS))
-  TESTS += test1
-endif
 
 RUN_TCC = $(NATIVE_DEFINES) -run $(TOPSRC)/tcc.c $(TCCFLAGS)
 DISAS = objdump -d

tests/tests2/Makefile

@@ -53,9 +53,6 @@ ifneq (,$(filter OpenBSD FreeBSD NetBSD,$(TARGETOS)))
  SKIP += 114_bound_signal.test # libc problem signal/fork
  SKIP += 116_bound_setjmp2.test # No TLS_FUNC/TLS_VAR in bcheck.c
 endif
-ifeq ($(TARGETOS),NetBSD)
-  SKIP += 113_btdll.test # text relocations
-endif
 
 # Some tests might need arguments
 ARGS =