<processthreadsapi.h> API's

[vatsan-madhavan]

As a follow-up to #428, I started looking into the rest of the API's missing from <processthreadsapi.h>. This is what I found so far:

Functions

• FlushInstructionCache
• FlushProcessWriteBuffers
• GetCurrentProcessorNumber
• GetCurrentProcessorNumberEx
• GetCurrentProcessToken
• GetCurrentThread
• GetCurrentThreadEffectiveToken
• GetCurrentThreadStackLimits
• GetCurrentThreadToken
• GetPriorityClass
• GetProcessHandleCount
• GetProcessIdOfThread
• GetProcessInformation
• GetProcessMitigationPolicy
• GetProcessPriorityBoost
• GetProcessShutdownParameters
• GetProcessVersion
• GetSystemTimes
• GetThreadContext
• GetThreadDescription
• GetThreadId
• GetThreadIdealProcessorEx
• GetThreadInformation
• GetThreadIOPendingFlag
• GetThreadPriority
• GetThreadPriorityBoost
• GetThreadTimes
• IsProcessCritical
• IsProcessorFeaturePresent
• OpenProcessToken
• OpenThread
• OpenThreadToken
• ProcessIdToSessionId
• QueryProcessAffinityUpdateMode
• QueryProtectedPolicy
• QueueUserAPC
• SetPriorityClass
• SetProcessAffinityUpdateMode
• SetProcessDynamicEHContinuationTargets
• SetProcessInformation
• SetProcessMitigationPolicy
• SetProcessPriorityBoost
• SetProtectedPolicy
• SetThreadContext
• SetThreadDescription
• SetThreadIdealProcessor
• SetThreadIdealProcessorEx
• SetThreadInformation
• SetThreadPriority
• SetThreadPriorityBoost
• SetThreadStackGuarantee
• SetThreadToken
• SwitchToThread
• TlsAlloc
• TlsFree
• TlsGetValue
• TlsSetValue

Structs/types

• APP_MEMORY_INFORMATION
• MEMORY_PRIORITY_INFORMATION
• PROCESS_LEAP_SECOND_INFO
• PROCESS_MEMORY_EXHAUSTION_INFO
• PROCESS_POWER_THROTTLING_STATE
• PROCESS_PROTECTION_LEVEL_INFORMATION
• THREAD_POWER_THROTTLING_STATE
• PROCESS_INFORMATION_CLASS
• PROCESS_MEMORY_EXHAUSTION_TYPE
• PROCESSOR_NUMBER

Additional types

• ProcessPriorityClass enum
  • An enum for process priority class values like ABOVE_NORMAL_PRIORITY_CLASS. This will be useful for functions like GetPriorityClass
• ThreadAccess enum
  • An enum with values like THREAD_ALL_ACCESS
• MemoryPriority enum
  • Memory priority for thread or process
• ProcessorPowerThrottlingFlags enum
  • Flags used with PROCESS_POWER_THROTTLING_STATE struct
• ProcessProtectionLevel enum
  • Process protection level values
• ProcessLeapSecondInfoFlags enum
  • Flags used in PROCESS_LEAP_SECOND_INFO fields

I have some of these implemented, and hope to contribute the rest in near future.