C++: Remove support for _Float128x which is not actually supported by gcc

Author: jketema

cpp/ql/lib/semmle/code/cpp/Type.qll

@@ -814,9 +814,6 @@ private predicate floatingPointTypeMapping(
   // _Float128
   kind = 49 and base = 2 and domain = TRealDomain() and realKind = 49 and extended = false
   or
-  // _Float128x
-  kind = 50 and base = 2 and domain = TRealDomain() and realKind = 50 and extended = true
-  or
   // _Float16
   kind = 52 and base = 2 and domain = TRealDomain() and realKind = 52 and extended = false
   or

cpp/ql/test/library-tests/templates/type_instantiations/types.expected

@@ -13,7 +13,6 @@
 | file://:0:0:0:0 | _Float64 |
 | file://:0:0:0:0 | _Float64x |
 | file://:0:0:0:0 | _Float128 |
-| file://:0:0:0:0 | _Float128x |
 | file://:0:0:0:0 | _Imaginary double |
 | file://:0:0:0:0 | _Imaginary float |
 | file://:0:0:0:0 | _Imaginary long double |

cpp/ql/test/library-tests/type_sizes/type_sizes.expected

@@ -33,7 +33,6 @@
 | file://:0:0:0:0 | _Float64 | 8 |
 | file://:0:0:0:0 | _Float64x | 16 |
 | file://:0:0:0:0 | _Float128 | 16 |
-| file://:0:0:0:0 | _Float128x | 32 |
 | file://:0:0:0:0 | _Imaginary double | 8 |
 | file://:0:0:0:0 | _Imaginary float | 4 |
 | file://:0:0:0:0 | _Imaginary long double | 16 |

cpp/ql/test/library-tests/unspecified_type/types/unspecified_type.expected

@@ -15,7 +15,6 @@
 | file://:0:0:0:0 | _Float64 | _Float64 |
 | file://:0:0:0:0 | _Float64x | _Float64x |
 | file://:0:0:0:0 | _Float128 | _Float128 |
-| file://:0:0:0:0 | _Float128x | _Float128x |
 | file://:0:0:0:0 | _Imaginary double | _Imaginary double |
 | file://:0:0:0:0 | _Imaginary float | _Imaginary float |
 | file://:0:0:0:0 | _Imaginary long double | _Imaginary long double |

cpp/ql/test/library-tests/variables/variables/types.expected

@@ -14,7 +14,6 @@
 | _Float64 | BinaryFloatingPointType, RealNumberType |  |  |  |  |
 | _Float64x | BinaryFloatingPointType, RealNumberType |  |  |  |  |
 | _Float128 | BinaryFloatingPointType, RealNumberType |  |  |  |  |
-| _Float128x | BinaryFloatingPointType, RealNumberType |  |  |  |  |
 | _Imaginary double | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |
 | _Imaginary float | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |
 | _Imaginary long double | BinaryFloatingPointType, ImaginaryNumberType |  |  |  |  |