linker: Require an exact matching signature when looking for prototypes.

Fixes piglit test glsl-override-builtin.  The linker incorrectly found
the prototype for the float signature, rather than adding a new
prototype with the int return type.  This caused ir_calls with type int
to have their callees set to the float signature, triggering an assert.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/glsl/link_functions.cpp b/src/glsl/link_functions.cpp
index 6374573e614..78c8b48cf17 100644
--- a/src/glsl/link_functions.cpp
+++ b/src/glsl/link_functions.cpp
@@ -111,7 +111,7 @@ public:
 	 f = new(linked) ir_function(name);
 
       ir_function_signature *linked_sig =
-	 f->matching_signature(&callee->parameters);
+	 f->exact_matching_signature(&callee->parameters);
       if (linked_sig == NULL) {
 	 linked_sig = new(linked) ir_function_signature(callee->return_type);
 	 f->add_signature(linked_sig);