Use '-g' instead of '-g3' when compiling grub2.

The rpm-build's "debugedit" program will silently corrupt .debug_macro
strings when a binary is compiled with -g3.  Later in the build phase,
gdb-add-index is invoked to extract the DWARF index from the binary,
and GDB will segfault because dwarf2read.c:parse_definition_macro's
'body' variable is NULL.

Resolves: rhbz#1708780

grub.macros

@@ -17,7 +17,6 @@
 %global cflags_sed						\\\
 	sed							\\\
 		-e 's/-O. //g'					\\\
-		-e 's/-g /-g3 /g'				\\\
 		-e 's/-fplugin=annobin //g'			\\\
 		-e 's,-specs=/usr/lib/rpm/redhat/redhat-annobin-cc1 ,,g' \\\
 		-e 's/-fstack-protector[[:alpha:]-]\\+//g'	\\\

grub2.spec

@@ -7,7 +7,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.02
-Release:	87%{?dist}
+Release:	88%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -518,6 +518,10 @@ rm -r /boot/grub2.tmp/ || :
 %endif
 
 %changelog
+* Tue Jun 18 2019 Sergio Durigan Junior <sergiodj@redhat.com> - 2.02-88
+- Use '-g' instead of '-g3' when compiling grub2.
+  Resolves: rhbz#1708780
+
 * Tue Jun 11 2019 Javier Martinez Canillas <javierm@redhat.com> - 2.02-87
 - Rebuild for RPM 4.15