mesa: rename OPCODE_INT -> OPCODE_TRUNC

Trunc is a more accurate description; there's no type conversion involved.
diff --git a/src/mesa/shader/prog_instruction.c b/src/mesa/shader/prog_instruction.c
index 1033496..7e340ce 100644
--- a/src/mesa/shader/prog_instruction.c
+++ b/src/mesa/shader/prog_instruction.c
@@ -182,7 +182,6 @@
    { OPCODE_FLR,    "FLR",     1, 1 },
    { OPCODE_FRC,    "FRC",     1, 1 },
    { OPCODE_IF,     "IF",      1, 0 },
-   { OPCODE_INT,    "INT",     1, 1 },
    { OPCODE_KIL,    "KIL",     1, 0 },
    { OPCODE_KIL_NV, "KIL",     0, 0 },
    { OPCODE_LG2,    "LG2",     1, 1 },
@@ -230,6 +229,7 @@
    { OPCODE_TXL,    "TXL",     1, 1 },
    { OPCODE_TXP,    "TXP",     1, 1 },
    { OPCODE_TXP_NV, "TXP",     1, 1 },
+   { OPCODE_TRUNC,  "TRUNC",   1, 1 },
    { OPCODE_UP2H,   "UP2H",    1, 1 },
    { OPCODE_UP2US,  "UP2US",   1, 1 },
    { OPCODE_UP4B,   "UP4B",    1, 1 },