Add libdfp benchmarks to table

Author: mborland

doc/decimal/benchmarks.adoc

@@ -55,6 +55,15 @@ Run using an Intel i9-11900k chipset running RHEL 9.4 and GCC 11.4.1-3
 | `decimal128_fast`
 | 517,930
 | 8.801
+| GCC `_Decimal32`
+| 893,375
+| 15.181
+| GCC `_Decimal64`
+| 496,127
+| 8.431
+| GCC `_Decimal128`
+| 1,143,636
+| 19.434
 |===
 
 === M1 macOS Results
@@ -126,6 +135,15 @@ Run using an Intel i9-11900k chipset running RHEL 9.4 and GCC 11.4.1-3
 | `decimal128_fast`
 | 7,424,598
 | 146.615
+| GCC `_Decimal32`
+| 2,997,658
+| 50.939
+| GCC `_Decimal64`
+| 2,129,898
+| 36.193
+| GCC `_Decimal128`
+| 3,056,979
+| 51.947
 |===
 
 ==== Subtraction
@@ -156,6 +174,15 @@ Run using an Intel i9-11900k chipset running RHEL 9.4 and GCC 11.4.1-3
 | `decimal128_fast`
 | 2,114,185
 | 39.630
+| GCC `_Decimal32`
+| 2,006,964
+| 37.620
+| GCC `_Decimal64`
+| 1,324,796
+| 24.833
+| GCC `_Decimal128`
+| 2,783,553
+| 52.177
 |===
 
 ==== Multiplication
@@ -186,6 +213,15 @@ Run using an Intel i9-11900k chipset running RHEL 9.4 and GCC 11.4.1-3
 | `decimal128_fast`
 | 13,970,509
 | 288.070
+| GCC `_Decimal32`
+| 2,507,998
+| 51.714
+| GCC `_Decimal64`
+| 2,414,864
+| 49.794
+| GCC `_Decimal128`
+| 6,248,956
+| 128.852
 |===
 
 ==== Division
@@ -216,6 +252,15 @@ Run using an Intel i9-11900k chipset running RHEL 9.4 and GCC 11.4.1-3
 | `decimal128_fast`
 | 1,208,184
 | 15.480
+| GCC `_Decimal32`
+| 5,002,197
+| 64.093
+| GCC `_Decimal64`
+| 2,961,731
+| 37.900
+| GCC `_Decimal128`
+| 10,095,995
+| 129.360
 |===
 
 === M1 macOS Results