Increase warning level.

* conf/Makefile.common (CFLAGS_GNULIB): Add -Wno-redundant-decls
	-Wno-unreachable-code -Wno-conversion -Wno-old-style-definition.
	* configure.ac (HOST_CFLAGS): Add bunch of -W arguments.
	(TARGET_CFLAGS): Likewise.
	(HOST_CFLAGS): Add -Werror unless --disable-werror is activated.
	* grub-core/Makefile.core.def (decompressor_xz): Add
	-Wno-unreachable-code.
	(normal): Add -Wno-redundant-decls.
	(xzio): Add -Wno-unreachable-code.
	(lzopio): Add -Wno-redundant-decls -Wno-error.
	* grub-core/commands/acpi.c: Add exception to -Wcast-align.
	* grub-core/commands/lsacpi.c: Add exception to -Wcast-align.
	* grub-core/gensymlist.sh: Add exception to -Wmissing-format-attribute.
	* grub-core/kern/dl.c: Add exception to -Wcast-align.
	* grub-core/kern/efi/efi.c (grub_efi_modules_addr): Likewise.
	* grub-core/kern/i386/coreboot/init.c: Add exception to
	-Wsuggest-attribute=noreturn.
	* grub-core/kern/ia64/dl.c: Add exception to -Wcast-align.
	* grub-core/kern/ia64/dl_helper.c: Likewise.
	* grub-core/kern/mips/dl.c: Likewise.
	* grub-core/kern/sparc64/dl.c: Likewise.
	* grub-core/lib/LzmaEnc.c: Add exception to -Wshadow.
	* grub-core/lib/libgcrypt_wrap/cipher_wrap.h (memcpy): Likewise.
	(memcmp): Likewise.
	* grub-core/lib/pbkdf2.c: Add exception to -Wunreachable-code.
	* grub-core/loader/ia64/efi/linux.c: Add exception to -Wcast-align.
	* grub-core/loader/mips/linux.c: Likewise.
	* grub-core/loader/multiboot_elfxx.c: Likewise.
	* grub-core/script/parser.y: Add exception to -Wunreachable-code.
	* grub-core/video/sm712.c: Add exception to -Wcast-align.
	* util/import_gcry.py: Add -Wno-cast-align to modules checked by hand.
	* grub-core/font/font.c (grub_font_loader_init): Add explicit cast and
	fixme.
	* grub-core/fs/iso9660.c (grub_iso9660_iterate_dir): Likewise.
	* grub-core/kern/i386/multiboot_mmap.c (grub_machine_mmap_init):
	Fix prototype.

grub-core/kern/dl.c

@@ -44,6 +44,8 @@
 
 
 
+#pragma GCC diagnostic ignored "-Wcast-align"
+
 grub_dl_t grub_dl_head = 0;
 
 static grub_err_t

grub-core/kern/efi/efi.c

@@ -203,6 +203,8 @@ grub_get_rtc (void)
   return grub_rtc_get_time_ms ();
 }
 
+#pragma GCC diagnostic ignored "-Wcast-align"
+
 /* Search the mods section from the PE32/PE32+ image. This code uses
    a PE32 header, but should work with PE32+ as well.  */
 grub_addr_t
@@ -246,6 +248,8 @@ grub_efi_modules_addr (void)
   return (grub_addr_t) info;
 }
 
+#pragma GCC diagnostic error "-Wcast-align"
+
 char *
 grub_efi_get_filename (grub_efi_device_path_t *dp)
 {

grub-core/kern/i386/coreboot/init.c

@@ -42,6 +42,8 @@ extern grub_uint8_t _start[];
 extern grub_uint8_t _end[];
 extern grub_uint8_t _edata[];
 
+#pragma GCC diagnostic warning "-Wsuggest-attribute=noreturn"
+
 grub_uint32_t
 grub_get_rtc (void)
 {

grub-core/kern/i386/multiboot_mmap.c

@@ -34,7 +34,7 @@ static struct multiboot_info kern_multiboot_info;
 static grub_uint8_t mmap_entries[sizeof (struct multiboot_mmap_entry) * 32];
 
 void
-grub_machine_mmap_init ()
+grub_machine_mmap_init (void)
 {
   if (! startup_multiboot_info)
     grub_fatal ("Unable to find Multiboot Information (is CONFIG_MULTIBOOT disabled in coreboot?)");

grub-core/kern/ia64/dl.c

@@ -39,6 +39,8 @@ grub_arch_dl_check_header (void *ehdr)
   return GRUB_ERR_NONE;
 }
 
+#pragma GCC diagnostic ignored "-Wcast-align"
+
 #define MASK20 ((1 << 20) - 1)
 #define MASK19 ((1 << 19) - 1)
 

grub-core/kern/ia64/dl_helper.c

@@ -23,6 +23,8 @@
 #include <grub/err.h>
 #include <grub/mm.h>
 
+#pragma GCC diagnostic ignored "-Wcast-align"
+
 void
 grub_ia64_dl_get_tramp_got_size (const void *ehdr, grub_size_t *tramp,
 				 grub_size_t *got)

grub-core/kern/mips/dl.c

@@ -49,6 +49,8 @@ grub_arch_dl_check_header (void *ehdr)
   return GRUB_ERR_NONE;
 }
 
+#pragma GCC diagnostic ignored "-Wcast-align"
+
 /* Relocate symbols.  */
 grub_err_t
 grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr)

grub-core/kern/sparc64/dl.c

@@ -38,6 +38,7 @@ grub_arch_dl_check_header (void *ehdr)
   return GRUB_ERR_NONE;
 }
 
+#pragma GCC diagnostic ignored "-Wcast-align"
 
 /* Relocate symbols.  */
 grub_err_t