doc: fix various fragment links

R=dsymonds
CC=golang-dev
https://golang.org/cl/7094058

doc/articles/c_go_cgo.html

@@ -149,9 +149,9 @@ is more complex than a single function call), as in this rewrite of
 </p>
 
 <p>
-To build cgo packages, just use <a href="/cmd/go/#Compile_packages_and_dependencies">"
+To build cgo packages, just use <a href="/cmd/go/#hdr-Compile_packages_and_dependencies">"
 <code>go build</code>"</a> or
-<a href="/cmd/go/#Compile_and_install_packages_and_dependencies">"<code>go install</code>
+<a href="/cmd/go/#hdr-Compile_and_install_packages_and_dependencies">"<code>go install</code>
 "</a> as usual. The go tool recognizes the special <code>"C"</code> import and automatically
 uses cgo for those files.
 </p>

doc/articles/go_command.html

@@ -48,7 +48,7 @@ had to be installed in certain places, under certain names, using certain build
 tools, in order to be used. That's understandable: that's the way it works in
 most other languages. Over the last few years we consistently reminded people
 about the <code>goinstall</code> command
-(now replaced by <a href="/cmd/go/#Download_and_install_packages_and_dependencies"><code>go get</code></a>)
+(now replaced by <a href="/cmd/go/#hdr-Download_and_install_packages_and_dependencies"><code>go get</code></a>)
 and its conventions: first, that the import path is derived in a known way from
 the URL of the source code; second, that the place to store the sources in
 the local file system is derived in a known way from the import path; third,

doc/articles/laws_of_reflection.html

@@ -213,7 +213,7 @@ type: float64
 You might be wondering where the interface is here, since the program looks
 like it's passing the <code>float64</code> variable <code>x</code>, not an
 interface value, to <code>reflect.TypeOf</code>. But it's there; as
-<a href="/pkg/reflect/#Type.TypeOf">godoc reports</a>, the signature of
+<a href="/pkg/reflect/#TypeOf">godoc reports</a>, the signature of
 <code>reflect.TypeOf</code> includes an empty interface:
 </p>
 

doc/code.html

@@ -406,7 +406,7 @@ ok  	example/newmath 0.165s
 </pre>
 
 <p>
-Run <code><a href="/cmd/go/#Test_packages">go help test</a></code> and see the
+Run <code><a href="/cmd/go/#hdr-Test_packages">go help test</a></code> and see the
 <a href="/pkg/testing/">testing package documentation</a> for more detail.
 </p>
 
@@ -486,7 +486,7 @@ is a list of external Go projects including programs and libraries.
 
 <p>
 For more information on using remote repositories with the <code>go</code> command, see
-<code><a href="/cmd/go/#Remote_import_path_syntax">go help remote</a></code>.
+<code><a href="/cmd/go/#hdr-Remote_import_path_syntax">go help remote</a></code>.
 </p>
 
 

doc/go_faq.html

@@ -1263,7 +1263,7 @@ each closure shares that single variable. When the closure runs, it prints the
 value of <code>v</code> at the time <code>fmt.Println</code> is executed,
 but <code>v</code> may have been modified since the goroutine was launched. 
 To help detect this and other problems before they happen, run
-<a href="http://golang.org/cmd/go/#Run_go_tool_vet_on_packages"><code>go vet</code></a>.
+<a href="http://golang.org/cmd/go/#hdr-Run_go_tool_vet_on_packages"><code>go vet</code></a>.
 </p>
 
 <p>
@@ -1359,7 +1359,7 @@ builds a test binary, and runs it.
 
 <p>See the <a href="/doc/code.html">How to Write Go Code</a> document,
 the <a href="/pkg/testing/"><code>testing</code></a> package
-and the <a href="/cmd/go/#Test_packages"><code>go test</code></a> subcommand for more details.
+and the <a href="/cmd/go/#hdr-Test_packages"><code>go test</code></a> subcommand for more details.
 </p>
 
 <h3 id="testing_framework">