[tools]: Minor intrinsic-gen changes

Have the resolver emit unique parameter names

Aslo: Update the parser tests to include ':' between parameter name and type.
This functionality landed a few changes up, but I missed this test from the change.

Bug: tint:832
Change-Id: If0d6d3a33bbcd8be4d70ee7182754158ed0da819
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/52641
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: David Neto <dneto@google.com>

tools/src/cmd/intrinsic-gen/parser/parser_test.go

diff --git a/tools/src/cmd/intrinsic-gen/parser/parser_test.go b/tools/src/cmd/intrinsic-gen/parser/parser_test.go
index 009aa7c..dddb166 100644
--- a/tools/src/cmd/intrinsic-gen/parser/parser_test.go
+++ b/tools/src/cmd/intrinsic-gen/parser/parser_test.go
@@ -96,7 +96,7 @@
 				},
 			}},
 		}},
-		{"fn F(a T)", ast.AST{
+		{"fn F(a: T)", ast.AST{
 			Functions: []ast.FunctionDecl{{
 				Name: "F",
 				Parameters: ast.Parameters{
@@ -128,7 +128,7 @@
 				},
 			}},
 		}},
-		{"fn F<T>(a X, b Y<T>)", ast.AST{
+		{"fn F<T>(a: X, b: Y<T>)", ast.AST{
 			Functions: []ast.FunctionDecl{{
 				Name: "F",
 				TemplateParams: ast.TemplateParams{

tools/src/cmd/intrinsic-gen/resolver/resolve.go

diff --git a/tools/src/cmd/intrinsic-gen/resolver/resolve.go b/tools/src/cmd/intrinsic-gen/resolver/resolve.go
index 792a33a..1798d0d 100644
--- a/tools/src/cmd/intrinsic-gen/resolver/resolve.go
+++ b/tools/src/cmd/intrinsic-gen/resolver/resolve.go
@@ -16,6 +16,7 @@
 
 import (
 	"fmt"
+	"sort"
 
 	"dawn.googlesource.com/tint/tools/src/cmd/intrinsic-gen/ast"
 	"dawn.googlesource.com/tint/tools/src/cmd/intrinsic-gen/sem"
@@ -65,6 +66,9 @@
 		}
 	}
 
+	// Calculate the unique parameter names
+	r.s.UniqueParameterNames = r.calculateUniqueParameterNames()
+
 	return r.s, nil
 }
 
@@ -444,6 +448,25 @@
 	return ty, nil
 }
 
+// calculateUniqueParameterNames() iterates over all the parameters of all
+// overloads, calculating the list of unique parameter names
+func (r *resolver) calculateUniqueParameterNames() []string {
+	set := map[string]struct{}{"": {}}
+	names := []string{}
+	for _, f := range r.s.Functions {
+		for _, o := range f.Overloads {
+			for _, p := range o.Parameters {
+				if _, dup := set[p.Name]; !dup {
+					set[p.Name] = struct{}{}
+					names = append(names, p.Name)
+				}
+			}
+		}
+	}
+	sort.Strings(names)
+	return names
+}
+
 // describe() returns a string describing a sem.Named
 func describe(n sem.Named) string {
 	switch n := n.(type) {

tools/src/cmd/intrinsic-gen/sem/sem.go

diff --git a/tools/src/cmd/intrinsic-gen/sem/sem.go b/tools/src/cmd/intrinsic-gen/sem/sem.go
index 9cf135b..1a615fe 100644
--- a/tools/src/cmd/intrinsic-gen/sem/sem.go
+++ b/tools/src/cmd/intrinsic-gen/sem/sem.go
@@ -29,6 +29,8 @@
 	MaxOpenTypes int
 	// Maximum number of open-numbers used across all intrinsics
 	MaxOpenNumbers int
+	// The alphabetically sorted list of unique parameter names
+	UniqueParameterNames []string
 }
 
 // New returns a new Sem