message: Adding more info on macro table in documentation
diff: @@ -794,16 +794,16 @@ preprocessor runs:
  * - Symbol name
  - Value
  - - Use
  + - Description
  * - ISPC
  - 1
  - - Detecting that the ``ispc`` compiler is processing the file
  + - Enables detecting that the ``ispc`` compiler is processing the file
  * - ISPC_TARGET_{NEON, SSE2, SSE4, AVX, AVX2, AVX512KNL, AVX512SKX}
  - 1
  - - One of these will be set, depending on the compilation target.
  + - One of these will be set, depending on the compilation target
  * - ISPC_POINTER_SIZE
  - 32 or 64
  - - Number of bits used to represent a pointer for the target architecture.
  + - Number of bits used to represent a pointer for the target architecture
  * - ISPC_MAJOR_VERSION
  - 1
  - Major version of the ``ispc`` compiler/language
  @@ -814,17 +814,20 @@ preprocessor runs:
  - 3.1415926535
  - Mathematics
  * - TARGET_WIDTH
  - - Vector width of the target, e.g., 8 for sse2-i32x8.
  - - Static varying initialization.
  + - Vector width of the target, e.g., 8 for sse2-i32x8
  + - Can be used for code versioning for static varying initialization
  * - TARGET_ELEMENT_WIDTH
  - - Element width in bytes, e.g., 4 for i32.
  - - Static varying initialization.
  + - Element width in bytes, e.g., 4 for i32
  + - Can be used for code versioning for static varying initialization
  * - ISPC_UINT_IS_DEFINED
  - - 1.
  - - Detecting if uint8/uint16/uint32/uint64 types are defined in the ISPC version.
  + - 1
  + - The macro is defined if uint8/uint16/uint32/uint64 types are defined in the ``ispc`` (it's defined in 1.13.0 and later)
  * - ISPC_FP64_SUPPORTED
  - - 1.
  - - Detecting if double type is supported by the target.
  + - 1
  + - The macro is defined if double type is supported by the target
  + * - ISPC_LLVM_INTRINSICS_ENABLED
  + - 1
  + - The macro is defined if LLVM intrinsics support is enabled
  ``ispc`` supports the following ``#pragma`` directives.
  @@ -3502,7 +3505,7 @@ For example:
  transpose = @llvm.matrix.transpose.v8f32.i32.i32(matrix, row, column);
  -To detect if this feature is enabled during runtime, check if ``ISPC_LLVM_INTRINSICS_ENABLED``
  +To detect if this feature is enabled during compile time, check if ``ISPC_LLVM_INTRINSICS_ENABLED``
  macro is defined.
  