amdgcn: Use __constant AS for amdgcn builtins.

Fixes build after clang r338707.
Reviewer: Matthew.Arsenault@amd.com
Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>

llvm-svn: 338898
GitOrigin-RevId: faa1ff16c1716d92d907060f713a14fbca4a7ea7
diff --git a/amdgcn-amdhsa/lib/workitem/get_global_size.cl b/amdgcn-amdhsa/lib/workitem/get_global_size.cl
index 2289615..392cd08 100644
--- a/amdgcn-amdhsa/lib/workitem/get_global_size.cl
+++ b/amdgcn-amdhsa/lib/workitem/get_global_size.cl
@@ -1,6 +1,8 @@
 #include <clc/clc.h>
 
-#if __clang_major__ >= 7
+#if __clang_major__ >= 8
+#define CONST_AS __constant
+#elif __clang_major__ >= 7
 #define CONST_AS __attribute__((address_space(4)))
 #else
 #define CONST_AS __attribute__((address_space(2)))
diff --git a/amdgcn-amdhsa/lib/workitem/get_local_size.cl b/amdgcn-amdhsa/lib/workitem/get_local_size.cl
index 034c6d9..64d1cf4 100644
--- a/amdgcn-amdhsa/lib/workitem/get_local_size.cl
+++ b/amdgcn-amdhsa/lib/workitem/get_local_size.cl
@@ -1,6 +1,8 @@
 #include <clc/clc.h>
 
-#if __clang_major__ >= 7
+#if __clang_major__ >= 8
+#define CONST_AS __constant
+#elif __clang_major__ >= 7
 #define CONST_AS __attribute__((address_space(4)))
 #else
 #define CONST_AS __attribute__((address_space(2)))
diff --git a/amdgcn/lib/workitem/get_global_offset.cl b/amdgcn/lib/workitem/get_global_offset.cl
index 0c2b948..0a87cd2 100644
--- a/amdgcn/lib/workitem/get_global_offset.cl
+++ b/amdgcn/lib/workitem/get_global_offset.cl
@@ -1,6 +1,8 @@
 #include <clc/clc.h>
 
-#if __clang_major__ >= 7
+#if __clang_major__ >= 8
+#define CONST_AS __constant
+#elif __clang_major__ >= 7
 #define CONST_AS __attribute__((address_space(4)))
 #else
 #define CONST_AS __attribute__((address_space(2)))
diff --git a/amdgcn/lib/workitem/get_work_dim.cl b/amdgcn/lib/workitem/get_work_dim.cl
index 8eb81ba..3add9b6 100644
--- a/amdgcn/lib/workitem/get_work_dim.cl
+++ b/amdgcn/lib/workitem/get_work_dim.cl
@@ -1,6 +1,8 @@
 #include <clc/clc.h>
 
-#if __clang_major__ >= 7
+#if __clang_major__ >= 8
+#define CONST_AS __constant
+#elif __clang_major__ >= 7
 #define CONST_AS __attribute__((address_space(4)))
 #else
 #define CONST_AS __attribute__((address_space(2)))