Fix libaom build dir collision with source tree's build/cmake/

libaom ships a build/cmake/ directory containing its cmake modules.
Using -B build overwrites this, causing include() failures. Renamed
the build directory to builddir, matching the Unix builder convention.

Author: Hendrik Mennen

src/SPC/builder/windows/library/libaom.php

@@ -12,14 +12,16 @@ class libaom extends WindowsLibraryBase
 
     protected function build(): void
     {
-        // reset cmake
-        FileSystem::resetDir($this->source_dir . '\build');
+        // libaom source tree contains a build/cmake/ directory with its own
+        // cmake modules, so we must use a different name for the build dir
+        // to avoid collisions.
+        FileSystem::resetDir($this->source_dir . '\builddir');
 
         // start build
         cmd()->cd($this->source_dir)
             ->execWithWrapper(
                 $this->builder->makeSimpleWrapper('cmake'),
-                '-S . -B build ' .
+                '-S . -B builddir ' .
                 '-A x64 ' .
                 "-DCMAKE_TOOLCHAIN_FILE={$this->builder->cmake_toolchain_file} " .
                 '-DCMAKE_BUILD_TYPE=Release ' .
@@ -34,7 +36,7 @@ protected function build(): void
             )
             ->execWithWrapper(
                 $this->builder->makeSimpleWrapper('cmake'),
-                "--build build --config Release --target install -j{$this->builder->concurrency}"
+                "--build builddir --config Release --target install -j{$this->builder->concurrency}"
             );
     }
 }