bfd, binutils, gas: Remove/mark unused variables

Clang generates a warning on unused (technically, written but not read
thereafter) variables.  By the default configuration (with "-Werror"), it
causes a build failure (unless "--disable-werror" is specified).

This commit adds ATTRIBUTE_UNUSED attribute to some of them, which means
they are *possibly* unused (can be used but no warnings occur when
unused) and removes others.

bfd/ChangeLog:

	* elf32-lm32.c (lm32_elf_size_dynamic_sections): Mark unused
	rgot_count variable.
	* elf32-nds32.c (elf32_nds32_unify_relax_group): Remove unused
	count variable.
	* mmo.c (mmo_scan): Mark unused lineno variable.

binutils/ChangeLog:

	* windmc.c (write_rc): Remove unused i variable.

gas/ChangeLog:

	* config/tc-riscv.c (riscv_ip): Remove unused argnum variable.

ld/ChangeLog:

	* pe-dll.c (generate_reloc): Remove unused bi and page_count
	variables.

3 files changed, 2 insertions, 5 deletions

diff --git a/bfd/elf32-lm32.c b/bfd/elf32-lm32.c
index 4830ab2..64b3ede 100644
--- a/bfd/elf32-lm32.c
+++ b/bfd/elf32-lm32.c
@@ -2067,7 +2067,7 @@ lm32_elf_size_dynamic_sections (bfd *output_bfd,
       struct weak_symbol_list *list_start = NULL, *list_end = NULL;
       int rgot_weak_count = 0;
       int r32_count = 0;
-      int rgot_count = 0;
+      int rgot_count ATTRIBUTE_UNUSED = 0;
       /* Look for deleted sections.  */
       for (ibfd = info->input_bfds; ibfd != NULL; ibfd = ibfd->link.next)
 	{
diff --git a/bfd/elf32-nds32.c b/bfd/elf32-nds32.c
index 82c2059..35e0302 100644
--- a/bfd/elf32-nds32.c
+++ b/bfd/elf32-nds32.c
@@ -13460,7 +13460,6 @@ elf32_nds32_unify_relax_group (bfd *abfd, asection *asec)
   Elf_Internal_Rela *relocs = NULL;
   enum elf_nds32_reloc_type rtype;
   struct section_id_list_t *node = NULL;
-  int count = 0;
 
   do
     {
@@ -13499,8 +13498,6 @@ elf32_nds32_unify_relax_group (bfd *abfd, asection *asec)
 
 	  /* Change it.  */
 	  rel->r_addend += relax_group_ptr->bias;
-	  /* Debugging count.  */
-	  count++;
 	}
     }
   while (false);
diff --git a/bfd/mmo.c b/bfd/mmo.c
index fd92a34..ddcdd35 100644
--- a/bfd/mmo.c
+++ b/bfd/mmo.c
@@ -1602,7 +1602,7 @@ static bool
 mmo_scan (bfd *abfd)
 {
   unsigned int i;
-  unsigned int lineno = 1;
+  unsigned int lineno ATTRIBUTE_UNUSED = 1;
   bool error = false;
   bfd_vma vma = 0;
   asection *sec = NULL;