tgsi: allow negation of all integer types

It's valid because we reuse certain arithmetic operations
for both signed and unsigned types (e.g. uadd, umad, which
have a bit unfortunate naming)

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: José Fonseca <jfonseca@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>

src/gallium/docs/source/tgsi.rst

@@ -32,11 +32,8 @@ For inputs which have a floating point type, both absolute value and negation
 modifiers are supported (with absolute value being applied first).
 TGSI_OPCODE_MOV is considered to have float input type for applying modifiers.
 
-For inputs which have signed type only the negate modifier is supported. This
-includes instructions which are otherwise ignorant if the type is signed or
-unsigned, such as TGSI_OPCODE_UADD.
-
-For inputs with unsigned type no modifiers are allowed.
+For inputs which have signed or unsigned type only the negate modifier is
+supported.
 
 Instruction Set
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