[PATCH v2 3/3] build: Update to reflect minimum clang version 8.0

[Darren Kenny]

After doing some validation with clang from versions 3.8 and up, the
builds prior to version 8.0.0 fail due to the use of safemath functions
at link time.

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>

fix

Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
---
 INSTALL                 | 2 +-
 include/grub/safemath.h | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/INSTALL b/INSTALL
index 7bca64f69881..620dcceb4814 100644
--- a/INSTALL
+++ b/INSTALL
@@ -16,7 +16,7 @@ you don't have any of them, please obtain and install them 
before
 configuring the GRUB.
 
 * GCC 5.1.0 or later
-  Experimental support for clang 3.8.0 or later (results in much bigger 
binaries)
+  Experimental support for clang 8.0.0 or later (results in much bigger 
binaries)
   for i386, x86_64, arm (including thumb), arm64, mips(el), powerpc, sparc64
 * GNU Make
 * GNU Bison 2.3 or later
diff --git a/include/grub/safemath.h b/include/grub/safemath.h
index c17b89bba17b..c2e338263107 100644
--- a/include/grub/safemath.h
+++ b/include/grub/safemath.h
@@ -23,15 +23,15 @@
 
 #include <grub/compiler.h>
 
-/* These appear in gcc 5.1 and clang 3.8. */
-#if GNUC_PREREQ(5, 1) || CLANG_PREREQ(3, 8)
+/* These appear in gcc 5.1 and clang 8.0 */
+#if GNUC_PREREQ(5, 1) || CLANG_PREREQ(8, 0)
 
 #define grub_add(a, b, res)    __builtin_add_overflow(a, b, res)
 #define grub_sub(a, b, res)    __builtin_sub_overflow(a, b, res)
 #define grub_mul(a, b, res)    __builtin_mul_overflow(a, b, res)
 
 #else
-#error gcc 5.1 or newer or clang 3.8 or newer is required
+#error gcc 5.1 or newer or clang 8.0 or newer is required
 #endif
 
 #endif /* GRUB_SAFEMATH_H */
-- 
2.31.1