gopls: make 'fastfuzzy' the default fuzzy matcher for workspace symbols

For dense queries, the fastfuzzy matcher is around 3x faster. It also
has improved scoring for exact matches of CamelCase words or path
segments.

Fixes golang/go#50016

Change-Id: I04cae11cbc54de59d54733836876a9ee759c80b6
Reviewed-on: https://go-review.googlesource.com/c/tools/+/382394
Trust: Robert Findley <rfindley@google.com>
Run-TryBot: Robert Findley <rfindley@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
gopls-CI: kokoro <noreply+kokoro@google.com>

gopls/doc/settings.md

@@ -398,7 +398,7 @@ Must be one of:
 * `"FastFuzzy"`
 * `"Fuzzy"`
 
-Default: `"Fuzzy"`.
+Default: `"FastFuzzy"`.
 
 ##### **symbolStyle** *enum*
 

internal/lsp/source/api_json.go

@@ -185,7 +185,7 @@ var GeneratedAPIJSON = &APIJSON{
 					{Value: "\"FastFuzzy\""},
 					{Value: "\"Fuzzy\""},
 				},
-				Default:   "\"Fuzzy\"",
+				Default:   "\"FastFuzzy\"",
 				Status:    "advanced",
 				Hierarchy: "ui.navigation",
 			},

internal/lsp/source/options.go

@@ -133,7 +133,7 @@ func DefaultOptions() *Options {
 					},
 					NavigationOptions: NavigationOptions{
 						ImportShortcut: Both,
-						SymbolMatcher:  SymbolFuzzy,
+						SymbolMatcher:  SymbolFastFuzzy,
 						SymbolStyle:    DynamicSymbols,
 					},
 					CompletionOptions: CompletionOptions{