Add support for constants in the new go generator.

Builtin constants (NaN, infinity, negative infinity) are not supported.
BUG= Fixes #685
R=vardhan@google.com

Review URL: https://codereview.chromium.org/2233963003 .

Cr-Mirrored-From: https://github.com/domokit/mojo
Cr-Mirrored-Commit: bed778d1cd47decbeda08679159321480ce59fa2
diff --git a/tools/bindings/mojom_tool/bin/linux64/generators/go.sha1 b/tools/bindings/mojom_tool/bin/linux64/generators/go.sha1
index b2e965d..b292841 100644
--- a/tools/bindings/mojom_tool/bin/linux64/generators/go.sha1
+++ b/tools/bindings/mojom_tool/bin/linux64/generators/go.sha1
@@ -1 +1 @@
-73fa303dec52eca2d70b2830ccd2a358135f4a61
\ No newline at end of file
+214eadd152cc192b76dd03f755c00930e562ed54
\ No newline at end of file
diff --git a/tools/bindings/mojom_tool/bin/mac64/generators/go.sha1 b/tools/bindings/mojom_tool/bin/mac64/generators/go.sha1
index 63926e8..0deca73 100644
--- a/tools/bindings/mojom_tool/bin/mac64/generators/go.sha1
+++ b/tools/bindings/mojom_tool/bin/mac64/generators/go.sha1
@@ -1 +1 @@
-78f622393bafe75f1f8bd0d4618a4aa2d26abe08
\ No newline at end of file
+6a8635a298fc5d52d82ac309b133109f1d49e1cd
\ No newline at end of file