CBOR reader: inline get_cbor_float() and always inline get() instead

The never-inlined get_cbor_float() costs a call for every float read
from input without bulk access: reading canada.json from CBOR through a
FILE* became 5.6 % slower on Apple clang in the benchmark suite. The
helper existed only because GCC 13 stopped inlining the stream adapter's
get_character() into parse_cbor_internal. Always inlining
binary_reader::get() fixes that as well.

callgrind, all binary formats on buffer, std::istringstream and FILE*
input (canada and citm_catalog): GCC 13 0.986-1.003, GCC 16 0.994-1.006,
Clang 23 identical. Apple clang suite: FromBinaryFile/cbor/canada 0.939,
geomean of the 53 binary reader rows 0.998.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>

include/nlohmann/detail/input/binary_reader.hpp

@@ -1148,10 +1148,8 @@ class binary_reader
         }
     }
 
-    /// read a single- or double-precision float (kept out of
-    /// parse_cbor_value, which is inlined into parse_cbor_internal)
+    /// read a single- or double-precision float
     template<typename NumberType>
-    JSON_HEDLEY_NEVER_INLINE
     bool get_cbor_float()
     {
         NumberType number{};
@@ -4205,7 +4203,12 @@ class binary_reader
     `char_traits<char_type>::eof()` in that case.
 
     @return character read from the input
+
+    @note always inlined: GCC otherwise stops inlining the stream adapter's
+          get_character() into parse_cbor_internal once that function grows
+          (+0.45 % instructions for CBOR from a std::istringstream with GCC 13)
     */
+    JSON_HEDLEY_ALWAYS_INLINE
     char_int_type get()
     {
         ++chars_read;