[test]add test case for align pragma with character

Add test case to validate the effectiveness of the pragma
`!DIR$ ALIGN alignment` for character.

test/directives/align_character_variable.f90

@@ -0,0 +1,97 @@
+! RUN: %flang -O0 -S -emit-llvm %s -o - | FileCheck %s
+
+! CHECK: %struct[[BLOCK1:\.STATICS[0-9]+]] = type <{ [10 x i8] }
+! CHECK: %struct[[BLOCK2:\.STATICS[0-9]+]] = type <{ [10 x i8] }
+! CHECK: %struct[[BLOCK3:\.STATICS[0-9]+]] = type <{ [10 x i8] }
+! CHECK: %struct[[BLOCK4:\.STATICS[0-9]+]] = type <{ [10 x i8] }
+! CHECK: %struct[[BLOCK5:_module_align_character_[0-9]+_]] = type <{ [10 x i8] }
+! CHECK: %struct[[BLOCK6:_module_align_character_[0-9]+_]] = type <{ [10 x i8] }
+! CHECK: @[[BLOCK1]] = internal global %struct[[BLOCK1]] <{{[^>]+}}>, align 256
+! CHECK: @[[BLOCK2]] = internal global %struct[[BLOCK2]] <{{[^>]+}}>, align 512
+! CHECK: @[[BLOCK3]] = internal global %struct[[BLOCK3]] <{{[^>]+}}>, align 1024
+! CHECK: @[[BLOCK4]] = internal global %struct[[BLOCK4]] <{{[^>]+}}>, align 2048
+! CHECK: @[[BLOCK5]] = common global %struct[[BLOCK5]] zeroinitializer, align 128
+! CHECK: @[[BLOCK6]] = global %struct[[BLOCK6]] <{{[^>]+}}>, align 128
+
+module module_align_character
+implicit none
+
+    !DIR$ ALIGN 128
+    character(len=10) :: v1, v2 = "128"
+
+    interface
+        module subroutine module_interface_subroutine()
+        end subroutine module_interface_subroutine
+    end interface
+
+end module module_align_character
+
+submodule (module_align_character) submodule_align_character
+
+    contains
+    module subroutine module_interface_subroutine()
+
+        !DIR$ ALIGN 256
+        character(len=10) :: v3, v4 = "256"
+! CHECK:    %[[V3:v3_[0-9]+]] = alloca [10 x i8], align 256
+
+        v3 = "101"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr %[[V3]], align
+
+        v4 = "102"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK1]], align
+
+    end subroutine module_interface_subroutine
+end submodule submodule_align_character
+
+program align
+use module_align_character
+implicit none
+
+    !DIR$ ALIGN 512
+    character(len=10) :: v5, v6 = "512"
+! CHECK:    %[[V5:v5_[0-9]+]] = alloca [10 x i8], align 512
+
+    v5 = "201"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr %[[V5]], align
+
+    v6 = "202"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK2]], align
+
+    v1 = "81"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK5]], align
+
+    v2 = "82"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK6]], align
+
+end program align
+
+subroutine subroutine_align()
+
+    !DIR$ ALIGN 1024
+    character(len=10) :: v7, v8 = "1024"
+! CHECK:    %[[V7:v7_[0-9]+]] = alloca [10 x i8], align 1024
+
+    v7 = "401"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr %[[V7]], align
+
+    v8 = "402"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK3]], align
+
+    return
+end subroutine subroutine_align
+
+function function_align()
+
+    !DIR$ ALIGN 2048
+    character(len=10) :: v9, v10 = "2048"
+! CHECK:    %[[V9:v9_[0-9]+]] = alloca [10 x i8], align 2048
+
+    v9 = "801"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr %[[V9]], align
+
+    v10 = "802"
+! CHECK:      store volatile i64 %{{[0-9]+}}, ptr @[[BLOCK4]], align
+
+    return
+end function function_align