buildGo{Module,Package}: fix precedence for or operator

pkgs/build-support/go/module.nix

@@ -105,7 +105,7 @@ let
       runHook postConfigure
     '';
 
-    buildPhase = args.modBuildPhase or ''
+    buildPhase = args.modBuildPhase or (''
       runHook preBuild
     '' + lib.optionalString (deleteVendor == true) ''
       if [ ! -d vendor ]; then
@@ -133,7 +133,7 @@ let
       mkdir -p vendor
 
       runHook postBuild
-    '';
+    '');
 
     installPhase = args.modInstallPhase or ''
       runHook preInstall
@@ -176,7 +176,7 @@ let
     GOFLAGS = lib.optionals (!proxyVendor) [ "-mod=vendor" ] ++ lib.optionals (!allowGoReference) [ "-trimpath" ];
     inherit CGO_ENABLED;
 
-    configurePhase = args.configurePhase or ''
+    configurePhase = args.configurePhase or (''
       runHook preConfigure
 
       export GOCACHE=$TMPDIR/go-cache
@@ -200,9 +200,9 @@ let
       fi
 
       runHook postConfigure
-    '';
+    '');
 
-    buildPhase = args.buildPhase or ''
+    buildPhase = args.buildPhase or (''
       runHook preBuild
 
       exclude='\(/_\|examples\|Godeps\|testdata'
@@ -282,7 +282,7 @@ let
       )
     '' + ''
       runHook postBuild
-    '';
+    '');
 
     doCheck = args.doCheck or true;
     checkPhase = args.checkPhase or ''

pkgs/build-support/go/package.nix

@@ -99,7 +99,7 @@ let
 
     GOARM = toString (lib.intersectLists [(stdenv.hostPlatform.parsed.cpu.version or "")] ["5" "6" "7"]);
 
-    configurePhase = args.configurePhase or ''
+    configurePhase = args.configurePhase or (''
       runHook preConfigure
 
       # Extract the source
@@ -141,7 +141,7 @@ let
       fi
 
       runHook postConfigure
-    '';
+    '');
 
     renameImports = args.renameImports or (
       let
@@ -151,7 +151,7 @@ let
         renames = p: lib.concatMapStringsSep "\n" (rename p.goPackagePath) p.goPackageAliases;
       in lib.concatMapStringsSep "\n" renames inputsWithAliases);
 
-    buildPhase = args.buildPhase or ''
+    buildPhase = args.buildPhase or (''
       runHook preBuild
 
       runHook renameImports
@@ -235,7 +235,7 @@ let
       )
     '' + ''
       runHook postBuild
-    '';
+    '');
 
     doCheck = args.doCheck or false;
     checkPhase = args.checkPhase or ''