include cleanup using iwyu

src/pcm/PcmBuffer.cxx

@@ -19,7 +19,6 @@
 
 #include "config.h"
 #include "PcmBuffer.hxx"
-#include "poison.h"
 
 void *
 PcmBuffer::Get(size_t new_size)

src/pcm/PcmConvert.hxx

@@ -29,6 +29,7 @@
 #include <stddef.h>
 
 class Error;
+class Domain;
 
 /**
  * This object is statically allocated (within another struct), and
@@ -100,6 +101,6 @@ private:
 				  Error &error);
 };
 
-extern const class Domain pcm_convert_domain;
+extern const Domain pcm_convert_domain;
 
 #endif

src/pcm/PcmDsd.cxx

@@ -25,7 +25,6 @@
 #include <algorithm>
 
 #include <assert.h>
-#include <string.h>
 
 PcmDsd::PcmDsd()
 {

src/pcm/PcmDsdUsb.cxx

@@ -22,6 +22,8 @@
 #include "PcmBuffer.hxx"
 #include "AudioFormat.hxx"
 
+#include <assert.h>
+
 constexpr
 static inline uint32_t
 pcm_two_dsd_to_usb_marker1(uint8_t a, uint8_t b)

src/pcm/PcmMix.cxx

@@ -23,6 +23,7 @@
 #include "PcmUtils.hxx"
 #include "AudioFormat.hxx"
 
+#include <assert.h>
 #include <math.h>
 
 template<typename T, typename U, unsigned bits>