Re-write sentence about the header availability

main/acle.md

@@ -940,7 +940,8 @@ guaranteed to be available.
 arithmetic intrinsics. As these intrinsics are in the user namespace,
 an implementation would not normally define them until the header is
 included. When `__ARM_FEATURE_FP16_SCALAR_ARITHMETIC` is defined to `1`,
-the header file is guaranteed to be available.
+the header file is available regardless of the context in which the macro
+is evaluated.
 
 ``` c
   #ifdef __ARM_FEATURE_FP16_SCALAR_ARITHMETIC
@@ -953,8 +954,9 @@ the header file is guaranteed to be available.
 `<arm_bf16.h>` is provided to define the 16-bit brain floating point
 arithmetic intrinsics. As these intrinsics are in the user namespace,
 an implementation would not normally define them until the header is
-included. The `__ARM_FEATURE_BF16` is defined to `1`, the header file is
-guaranteed to be available in a normal unannotated function.
+included. When `__ARM_FEATURE_BF16` is defined to `1`, the header file is
+guaranteed to be available regardless of the context in which the macro
+is evaluated.
 
 ``` c
   #ifdef __ARM_FEATURE_BF16
@@ -975,8 +977,9 @@ instructions available are conversion intrinsics between `bfloat16_t` and
 intrinsics](#advanced-simd-neon-intrinsics) and associated
 [data types](#vector-data-types). As these intrinsics and data types are
 in the user namespace, an implementation would not normally define them
-until the header is included. The `__ARM_NEON` is defined to `1`,
-the header file is guaranteed to be available in a normal unannotated function.
+until the header is included. When `__ARM_NEON` is defined to `1`,
+the header file is available regardless of the context in which the macro is
+evaluated.
 
 
 ``` c
@@ -1000,8 +1003,8 @@ following it. --><span id="arm_sve.h"></span>
 `<arm_sve.h>` defines data types and intrinsics for SVE and its
 extensions; see [SVE language extensions and
 intrinsics](#sve-language-extensions-and-intrinsics) for details.
-The `__ARM_FEATURE_SVE` is defined to `1`, the header file is guaranteed to be
-available in a normal unannotated function.
+When `__ARM_FEATURE_SVE` is defined to `1`, the header file is available
+regardless of the context in which the macro is evaluated.
 
 ``` c
   #ifdef __ARM_FEATURE_SVE
@@ -1062,8 +1065,8 @@ change or be extended in the future.
 
 `<arm_sme.h>` declares functions and defines intrinsics for SME
 and its extensions; see [SME language extensions and intrinsics](#sme-language-extensions-and-intrinsics)
-for details. The `__ARM_FEATURE_SME` is defined to `1`,
-the header file is guaranteed to be available in a normal unannotated function.
+for details. When `__ARM_FEATURE_SME` is defined to `1`, the header file is
+available regardless of the context in which the macro is evaluated.
 
 ``` c
   #ifdef __ARM_FEATURE_SME